# Agent handoff — cross-machine continuity **Last updated: 2026-07-28, as bottom-panel Stage 2B-2 (#187) — the daemon panel projection and the epoch machine — lands on `6c9e765`, which is the dired Stage 2 framing (#171) atop the resource-op delete guard framing (#186). Those two are framing-only: both are approved documents with no runtime code, and neither has begun implementation. Beneath them, the docs-only coherence listview correction (#189) and landed-state refresh (#185); the canonical landed base beneath those is `7586905`. The runtime anchor beneath them is the M4 config-sink race fix (#174) and bottom-panel Stage 2B-1 (#184). #174 is test-only. #184 is the substantive one — the reserved protocol-v21 bottom-panel wire family, dark by construction, with the production handshake deliberately still advertising v20 — following the Journey/GPU directory-target ratchet (#183), following Journey Stage 1a (#182), which made directory startup one coherent local/daemon/GPU path and incorporated the terminal configuration + copy mode landed-doc work (#180); following terminal copy mode (#178) — `C-c C-t` materializes a terminal's whole retained range into an ordinary buffer, plus `Buffer::set_generated_contents`, the first genuinely immutable generated-buffer write path — and its landed-doc pair (#168); following Lean 4 Stage 4a (#179) — the typed-edit consumer chain — and bottom-panel Stage 2A (#177), the classified census routing that makes every Projection-class consumer ask `primary_document_window`; the bottom-panel Stage 2 framing (#175), terminal configuration Stage 1 (#173) — profiles, scrollback, a per-terminal configurable escape key, and the `C-c t` opening binding — Lean 4 stages 3a and 3b (#167, #170), pmacs' first Lean language server; the GPU terminal input fix (#166), the double terminal-layout sync that made a GPU terminal untypable; the CRDT undo repro (#157), the inline-math landed-doc refresh (#172), the inline-math slice (#158), the first mathematical typesetting in pmacs; dired Stage 1 (#165), Lean 4 Stage 2 (#161), the dired framing pair (#163/#164), find-file (#162) — the dired arc's Stage 0 — COHERENCE.md (#163), Lean 4 Stage 1 (#160), the minimap blank-slab fix (#159), bottom-panel Stage 1 (#155), the inline-math re-scout (#154), the vterm PTY-flake fix (#153), and the GPU initial-target doc refresh (#152); and before that GPU initial-target (#148, protocol v20), following folding Stage 2 (#149) and its landed-doc refresh (#150), web grammars HTML+CSS (#146), the LaTeX Stage 1 / inline-math framing pair (#144/#145), folding Stage 1 (#142), one-command GPU invocation (#141), the documentation refresh (#140), Vterm Stage 3 (#135), tab-width rendering parity (#137), locals-query processing (#134), modeline detection (#132), mode system wiring (#129), config registry (#127), Vterm Stages 1–2 (#126/#130), and completed Themes Arc 4 (#120/#124/#125).** This file is the bridge between development machines. If you are an agent reading this on a fresh clone: this document plus the `docs/*-framing.md` files ARE your memory. Read this fully before taking on work, seed your persistent memory from it, and **update this file (and commit it) whenever project state changes materially** — the next machine reads it the way you just did. For volatile branches, checkpoints, verification, and recovery commands, read `docs/active-work.md` immediately after this file. ## 1. Where the project stands (2026-07-28) - `main` @ `6c9e765` (the dired Stage 2 framing #171 and the resource-op delete guard framing #186 — both framing-only, no runtime code, no implementation started — atop the docs-only coherence listview correction #189, atop the docs-only landed-state refresh #185, the M4 config-sink race fix #174 — test-only — atop bottom-panel Stage 2B-1 #184, the Journey/GPU directory-target ratchet #183, Journey Stage 1a #182, incorporating terminal configuration + copy mode landed docs #180, Lean 4 Stage 4b #181, the dired Stage 1 landed docs #169 and the PTY-terminate diagnostic #176, terminal copy mode #178, the GPU-terminal-input landed docs #168, Lean 4 Stage 4a #179, bottom-panel Stage 2A #177, the bottom-panel Stage 2 framing #175, terminal configuration Stage 1 #173, Lean 4 Stage 3b #170, Stage 3a #167, the CRDT undo repro #157, the inline-math landed-doc refresh #172, the bottom-panel landed-doc refresh #156, the inline-math slice #158, dired Stage 1 #165, the GPU terminal input fix #166, Lean 4 Stage 2 #161, the dired framing #164, COHERENCE.md #163, find-file #162, Lean 4 Stage 1 #160, minimap blank-slab #159, bottom-panel Stage 1 #155). **Protocol schema support is now `v6..=v21`, while the production server-first `Hello` still advertises v20.** Those are two different facts and #184 landed only the first: the v21 bottom-panel wire family exists, is gated in both directions, and has no producer, no consumer, and no capability behind it. Compatible v21 activation and the production advertisement move belong to Stage 2B-3. The bullets below describe the arcs in their own terms; this line is the head-of-`main` anchor. - **`COHERENCE.md` is now required reading and a required framing input — #163.** It carries the product-coherence thesis, an audited scorecard, per-concern gaps, and §20's priority order, and it is the standard new work is evaluated against. Per `CLAUDE.md`, **every new framing doc must state its coherence impact** — journey steps touched, interaction islands added, config-registry adoption, background-work attribution. Its §2 grades the golden journey; **Journey Stage 1a moved that grade off "broken at step 3"** — see the arc bullet below. - **Journey arc (P1) — Stage 1a LANDED** (`docs/journey-stage1a-framing.md`). `pmacs .` opens a directory instead of exiting 1, on **one** path: `resolve_target_buffer` gained a `ResolvedTarget::Directory` arm *ahead* of the load, `EditorState::open` became a caller of it rather than a parallel implementation, and the daemon/GPU bootstrap shares the same arm. Which surface handles a directory is the `path.open-directory` chain with dired as a replaceable fallback slot. `tests/journey_acceptance.rs` is the new cross-subsystem ratchet (steps 2, 3, 5 seeded; **stages add rows, none removes them**). No protocol change. - **A hook a builtin subscribes to can never be first-claimant-wins for users.** `HookRegistry::add` only appends and builtins load before `init.lua`, so a dired subscription would always claim before any user listener. That is why dired is a *slot* (`pmacs.path.directory_handler`) and not a subscriber — and why clearing the slot has to leave startup succeeding with a status, not exiting 1. - **A raise and a `false` are indistinguishable in `proceed`.** `run_short_circuit` returns `proceed = false` for both; only `HookOutcome.errors` separates them, and it decides whether to *report*, not whether to fall back. Getting this backwards produces a fallback that runs after a user's resolver crashed mid-handling. - **The listing is async; the bootstrap is synchronous.** The whole post-await commit therefore runs against a destination captured at request time (`pmacs.window.commit_to`), which preflights every precondition *before* invoking the callback — dired mutates handle state, `prev`, and paint long before it reaches anything that could refuse, so validating at display time is four mutations too late. Awaiting inside a commit is refused: a yield would restore the scope while the coroutine is still parked. - **The scope swaps `core.active_frontend`, not just an override** — `pmacs.window.buffer()`'s no-arg arm reads the ambient active buffer directly, so dired's `prev` capture would otherwise follow whatever frontend happened to be dispatching. The override *also* exists, and is load-bearing in exactly one case: a commit reached from inside an interactive command, where the origin would otherwise outrank the ambient value. Bite-testing found N4 green without it. - **`replace_active_buffer` does not drop the startup scratch buffer**, despite its doc comment having claimed so for as long as it has existed. Its body is one `switch_active_buffer` call. The comment is corrected here; changing the lifetime is separate work. - Stage 1b is the named remainder: compile binding + Cargo defaults, LSP spawn guidance, welcome buffer. - **Terminal configuration + copy mode arc — COMPLETE** (`docs/terminal-config-and-copy-mode-framing.md` rev 4; Stage 1 #173, Stage 2 #178; no protocol change in either, still v20). Stage 1 ships profiles, scrollback, a per-terminal configurable escape key and the `C-c t` opener; Stage 2 ships copy mode — `M-x terminal.copy-mode` / `C-c C-t`. - **The snapshot MATERIALIZES into an ordinary buffer.** That is the arc's organizing decision: isearch, motion, selection and the kill ring work with no new substrate, and "keys must not reach the child" dissolves structurally, because the transport arm keys on `is_terminal(buffer_id)` and a snapshot is not a terminal. **The dispatch-shadow count therefore stays at six.** - **`prune` reacts to buffer removal rather than causing it** — it filters on `!registry.contains(buffer_id)`, so a child exiting does **not** remove the terminal buffer. That is what makes `on_removed` a sound teardown hook, and why a finished command's output stays readable. - **Ownership means "in our own handle table", never found-by-name** (dired's F7 rule, re-learned here): snapshot writes use `bypass_intercept`, so adopting a same-named foreign buffer clobbers user data. Snapshot identity is keyed by **comparing buffer handles in an array** — `BufferIdLua` implements `__eq` but each wrapper is a distinct table key, so comparison works and hashing does not. - **Profiles are a raw Lua table**, joining `pmacs.lsp.config` and `pmacs.pair.sets`, because `ConfigValue` is four scalars with no table kind. The two open-time settings resolve through the **global** chain (they are read before the identity buffer exists); only `terminal.escape-key` resolves per buffer, and its cache lives on **`TerminalSession`** so its lifetime is the terminal's — `value_epoch` alone is not a sufficient key, because it does not advance when focus moves between terminals holding different buffer-local values. - **Criterion 17 is deliberately unpinned, and its bite is now stated correctly.** A real semantic frontend proving neither copy is mutated needs the actual GPU binary (the optimistic apply exists only in `pmacs-gpu/src/main.rs`; the headless `SemanticClient` has no optimistic path), i.e. the `a37` footing §5 warns about. After `set_generated_contents` the eventual test must look for **unauthorized mirror mutation plus daemon refusal — divergence**, not the "mutates both sides silently" the criterion originally specified, which can no longer happen and would pass for the wrong reason. *A fix can invalidate a test that was never written.* - Test instruments worth reusing: **`cat -v` is the echo probe**, because the screen rejects C0 controls before they reach cells so a raw echoed `Ctrl-X` is invisible; and such probes must **count occurrences rather than test presence**, because a single-character probe collides with the child's own banner text. - **PTY terminate diagnostic LANDED — #176** (merge `bf8878f`, 2026-07-26, one review round; `docs/process-signal-tolerance-framing.md` rev 4, after three framing rounds). **Diagnostic only — no disposition changed.** Every call that failed before still fails, with no state transition and no reap-ledger arming; `src/process.rs` is the only source file touched. It exists because the `terminate` EPERM flake is real and nothing yet knows *why*. - **Why three tolerance rules were all rejected: each concluded something about a process from something that was not about that process.** Rev 1 reasoned from an errno alone (EPERM means the caller lacks permission, not that the id was recycled); rev 2 from `try_wait`, which observes the spawned **leader** while a PTY signal targets `-tcgetpgrp(...)` — entities that diverge exactly when job control has moved the terminal; rev 3 from group-directed **ESRCH**, which proves only that the selected foreground group vanished. This is the reusable shape, not a Unix trivium. - **Two facts that killed the original argument.** `group = true` is *rejected* for PTY mode at spawn, so the reap ledger never applies to the PTY path at all; and the ledger's own comment saying EPERM "cannot happen for our own children" drops the entry for **bounded growth**, not as a ruling that EPERM means dead. A comment stating a belief is not the same as code enforcing it. - What ships: a failing `kill` now reports five separate facts — target source, target kind/value, spawn-time group, errno, and the leader's real `try_wait` state. The test seam injects the **kill result only**, never the observation, so the real `ChildHandle::try_wait` runs against the real child. - **It is not "strictly additive".** `try_wait` reaps and caches, so an exited child may be reaped earlier than before. That is safe only because `portable-pty` 0.9.0 returns a `std::process::Child` on Unix and delegates `try_wait` to it, so `poll_one` still sees the cached status — pinned by an exactly-one-terminal-event test rather than assumed. - **Still open, and still the most likely real fix site:** `signal_target`'s read-then-kill of `tcgetpgrp`. All tolerance rules remain parked pending the evidence this diagnostic produces, as does `terminate` idempotence for an already-reaped process (a different failure, so a different PR). - **Lean 4 arc (Arc 8) — stages 1, 2, 3a, 3b, 4a, 4b ALL LANDED** (`docs/lean4-mode-framing.md`; #160, #161, #167, #170, #179, #181). pmacs edits Lean 4: `arborium-lean` highlighting, a `lean4` major mode, `⟨⟩ ⦃⦄ ⟮⟯` pairs, and a `lake serve` language server with a Lake-aware outermost root, a lazy toolchain probe, a one-shot `lean --server` fallback, and `waitForDiagnostics`. **No protocol change in any stage** (still v20). - **Two of the four stages contained no Lean at all**, and that is the arc's organizing rule: *no PR mixes a cross-cutting substrate change with Lean feature content.* Stage 2 made LSP server affinity per-project-root (`ensure_server` had been reusing one server across roots — a correctness bug for every language, not just Lean). Stage 3a added notification/response subscription seams to `handle_server_requests`, the single shared LSP event drain, plus `pmacs.fs.canonicalize`. - **Two consecutive re-scouts found that rule broken by the stage being scouted** — Stage 3 in round 4, Stage 4 in round 5, each time by a risk column that contradicted its own prose. The rule is not self-enforcing. Re-check every remaining stage's risk column at scout time. - **A configured LSP root must be a canonical absolute path.** It reaches `file_uri_for` verbatim and that URI is the affinity key, so one package opened by two spellings spawns two servers. Stage 3a's `pmacs.fs.canonicalize` is the primitive; it returns nil rather than a lossy path for non-UTF-8 input. - **`LspManager::stop` on an already-terminal client strands it in `ShuttingDown` forever** — `server_is_live` then counts it live so nothing rebuilds against it, and `forget` refuses it for not being terminal. *Stopping a dead server is what makes it un-replaceable.* Stage 3b works around it by dispatching on state (`forget` when terminal, `stop` when live); merely skipping the call leaves `next_restart_at` armed. The real fix is unframed substrate work. - **`elan` shims lie**: `lake --version` and `lean --version` can both fail ("no default toolchain configured") on a machine where Lean otherwise works, so `command -v lake` is worthless as a capability check. Lean acceptance is fake-server; live smokes must be PATH- **and** success-gated. - Stage 3b took six review rounds, and **the same defect appeared four times**: "the fallback silently doesn't happen," as no re-attach, then re-attach cleared by an unrelated buffer, then satisfied by the very server being replaced, then repairing one buffer while the rest stayed stale. Each fix was locally right; none asked what a *global* config swap invalidates. The durable lesson is to heal at **consumption** — the point where a stale record is handed out — not at the moment of the swap. - **Stage 4a (the typed-edit consumer chain) MERGED as #179** (branch `lean4-stage4a-typed-edit-chain`, framing rev 8; it is part of the main anchor above). It is substrate only: `builtin/runtime/typed_edit.lua` owns the single `buffer.after-edit` subscriber and the single one-shot read, `pair.lua` becomes its first registered consumer, and `tests/auto_pair_acceptance.rs` is unchanged by zero lines (criterion 46, verified at the diff). No protocol change, no Lean content. The three decisions that turned out load-bearing rather than stylistic: consumers are called **even when the record is nil** (three existing auto-pair tests assert the non-event through it, and 4b abandons stale pending state on it); each consumer gets its **own copy** of the record, because pairing reads `rec.char` and a declining consumer could otherwise forge it; and the fan-out iterates a **snapshot**, because a consumer that registers a lower-priority one shifts itself forward under `ipairs` and runs twice. - **Round 8's durable lesson: `run_all_must_succeed` does NOT abort the fan-out.** `src/hook.rs:332` collects each callback's error and continues to the remaining subscribers, marking only the run failed — so an uncontained throw inside a hook subscriber does not stop `lsp.lua` from flushing didChange. Two framing revisions asserted the opposite to justify a `pcall`. The guard was right and the reason was wrong, and by the time review caught it the wrong reason had been copied into a module comment, an acceptance criterion, a test comment, and the ledger. **Correct the source a rationale derives from, not only the sites that quote it.** - **Stage 4b (the Unicode input method) MERGED as #181** (framing rev 9): a vendored 1,855-entry table generated from `leanprover/vscode-lean4@17d1d08` by `scripts/regen-lean-abbrev`, plus a consumer registered on the Stage 4a chain at priority 50, ahead of pairing. **A consumer cannot both edit and let a later consumer act on the same keystroke**: the chain hands each consumer a copy of the record made before any consumer ran, so an edit invalidates every copy still to be used. The expansion therefore runs on a SECOND `buffer.after-edit` subscriber after the chain — which is how a pair character that terminates an abbreviation still pairs (`\alp(` → `α()`). And **deferring work past a fan-out means owning which fan-out it belongs to**: these fan-outs NEST, so a consumer between the expander and pairing that calls `pmacs.hook.run` re-enters the deferred subscriber while the outer chain is still mid-list, and the count that recognises this has to come from a MINIMUM-PRIORITY consumer — the expander is optional (a claim can stop the chain first) and a subscriber beside the deferred one is too late (the nested fan-out finishes inside the outer chain's subscriber). Its other durable facts: the table must stay an ORDERED SEQUENCE (equal-length ties resolve by source declaration order, which a `pairs`-iterated map cannot express); a generator round-trip check must re-read the BYTES ON DISK, because comparing in-memory strings cannot see an encoding applied by the write itself; and an expansion that SHRINKS the buffer must place the point explicitly, or every later self-insert is silently rejected and the editor looks dead. - **Round 9 corrected three approved acceptance criteria** by simulating the state machine over all 1,855 entries rather than re-reading the prose. Four review rounds over the text had not found them, because each named an example that reads as obviously right and is wrong only against the data. - Remaining: stages 5 (goal panel), 6 (`#eval` output channel), and 7 (module hierarchy) are framed but not scouted against current `main`. - **Inline math LANDED — #158** (`docs/inline-math-slice-framing.md` rev 3; merge `5aa9044`). pmacs renders `$…$` as typeset mathematics in the GPU frontend. **No protocol change (still v20); the whole slice lives in `pmacs-gpu`**, because `pmacs-gpu` depends only on `pmacs-protocol` and never on `pmacs` — a core-crate parser would have been unreachable from where rendering happens. - `math_parse.rs` → `math_layout.rs` → a `ChunkSource::MathBox` spacer chunk → per-glyph mini-buffers drawn at the shaped line's real baseline, with fraction rules as quads. Font is bundled Latin Modern Math (~717 KiB) under the **GUST Font License** — not OFL. - **The v0 subset is narrow and deliberately so**: Greek (34 entries), sub/superscript, and `\frac`. Everything else — including relations like `\geq`, fences, big operators, and all display math (`$$…$$`, `\[…\]`) — is a named deferral, and an unsupported command degrades the **whole span** back to source rather than rendering partially. In a real paper most inline spans still show source; that is the designed behaviour, not a defect. - **Math is suppressed while the caret is inside its span**, so editing always sees source. That gate reads the effective caret plus selection endpoints and is fed by three separate refresh triggers; it is the most delicate part of the slice. - Selection and search washes cover the whole box rectangle, not sub-ranges (sub-range washes are deferred). - TUI shows the LaTeX source unchanged. That divergence is recorded against `COHERENCE.md` §16, which audits the "no privileged frontend" rule. - **find-file LANDED — #162** (`docs/dired-framing.md` §10, Q#DR11; merge `2af1ab3`; one review round). `C-x C-f` is the dired arc's **Stage 0**: pmacs previously had no discoverable way to open a file by path — no such command existed and `pmacs.buffer.find_or_open` had no interactive caller. Pure Lua in `builtin/commands/default.lua`, one keymap line, an 8-test dispatch-driven acceptance suite; no Rust, no protocol change. Two substrate facts it documents, both worth knowing before touching any minibuffer prompt: - **Completion over files is flat and cannot be made hierarchical from Lua.** A custom `source` function is called with **zero arguments** (`minibuffer.rs:591`) and runs synchronously outside any coroutine, where `Handle:await()` raises — so it can neither see the input to re-root on nor list a directory. Only the Rust `CompletionSource::Files { root }` can list, and it is single-directory and 1024-capped. - **A selected candidate SHADOWS typed text.** `recompute_candidates` sets `selected = Some(0)` whenever the list is non-empty (`minibuffer.rs:372-377`) and `resolve_accepted_value` returns the candidate over the typed contents (`:564-574`). So free-text accept fires only when the input filters every candidate away — for basename candidates under a subsequence filter, when it contains a `/`. This applies to `M-x` and `switch-buffer` too. Consequences are pinned as decisions, including the hole where a new bare name that is a subsequence of an existing entry opens the existing file, and the empty-input case (`fuzzy_score` gives `Some(0)` for an empty needle and ties break lexicographically, so dotfiles lead). - Also: `get_or_load_buffer` computes a normalized path but **loads from the raw one** (`editor_core.rs:842-856`), so a `~/…` path dedups against an open buffer yet fails to load one that is not open — find-file expands the tilde Lua-side. Loading through the normalized path is a named deferral. - **dired Stage 1 — the directory view — LANDED — #165** (`docs/dired-framing.md` §0, S1-1…S1-12; merge `c8ec8f3`; one review round). pmacs now has a directory surface: `C-x d` / `C-x C-j` open a read-only listing, one buffer per directory named `*dired:*`, with a `dired` major mode whose mode-scoped keymap carries `RET`/`f`, `^`, `n`/`p`, `g`, `q`, `s`. Protocol unchanged at **v20**. **Stage 2 (marks and operations) and Stage 3 (wdired) each still need their own framing**; the frozen fixture shrinks after Stage 3. - **The Rust is confined to two things**: a per-entry-tolerant `read_dir` (`ReadDirTolerance {Fatal, PerEntry}` → `FsDirListing {entries, errors}`), because `read_dir_blocking` fails a whole listing on any of five per-entry conditions and the tolerant wrapper its own module doc delegates to package authors **cannot be written in Lua** (one error value, no partial vec); and `editor_core::normalize_buffer_path` becoming `pub`, exposed as `pmacs.path.canonicalize`. Only non-UTF-8 **names** stay fatal — byte-preserving paths would be needed. The Lua result **shape** keys on `errors.is_some()`, so the bare array the frozen M8.2 fixture consumes with `ipairs` is untouched. - **Exposing a core normalizer beat mirroring it in Lua.** A Lua mirror would have been a second canonical form — the same class of bug as the five tab-width constants (#137). Applies to any future Lua-side path reckoning. - **A fixed-width column must be fixed-width for every input.** The exported `pmacs.dired._layout` (MARK 0, KIND 2, PERMS 3–12, SIZE 13, MTIME 24, NAME 41) is the contract Stage 3 reads offsets from, and `%10d` overflows at ≥10 GB, silently shifting every column right of it. Sizes now fall back to a width-clamped magnitude (K/M/G/T/P/E). - **An ambient action must be gated on the buffer it assumes.** A revert's cursor re-seat settles a tick or more later, by which time the user may have switched buffers; the paint names its buffer and is safe, but seating is ambient. This is the buffer-level instance of the rule below that interactive origin does not survive an await. - **A failure IS an answer — don't probe first.** Kinds are lstat-based in both `read_dir` and `stat`, so nothing in an entry says whether a symlink points at a directory. `RET` tries to list it and treats the failure as the answer; an explicit probe was a second full `read_dir`, so a descent listed twice. - **Unbounded per-entry error collection needs a cap when nothing cancels the work.** A dired listing carries no supersede key, so cancellation was never the backstop the tolerant loop implicitly relied on (`READDIR_MAX_CONSECUTIVE_ENTRY_ERRORS = 1024`). - **This is the first builtin with mode-scoped keys** (#129's first non-detection consumer), which broke the pre-existing `describe_key_identifies_every_default_binding`: it asserted every binding resolves through `describe.key` context-free, which held only while the modes table was empty. It now sets the effective context per binding and explicitly **clears** the mode for global ones, because a leaked mode legitimately shadows a global chord of the same name (dired's `RET` shadows `edit.newline-and-indent`), plus a floor assertion that at least one mode-scoped binding exists. - **A dedicated panel does not carry its dedication across a descent** — the framing expected it to. `display_buffer` never replaces the buffer in a slot dedicated to another one; it discards every side-specific parameter and falls back to the document window (Q#BP3 2.iii), and the exact-window arm errors. Dired does not unpin the user's panel; both arms are pinned. - Smaller facts worth knowing before touching this code: a path-backed buffer's **name is its full path**, not its basename, which matters for any name assertion; `pmacs.buffer.kill` (not `remove`) redirects windows off a doomed buffer first, so `dired.kill-when-opening` kills **after** the replacement is displayed; ownership is checked against the handle table only, never the buffer name; and `C-x d` takes **no** completion source on purpose (with one, `RET` on an empty field opens whatever sorts first, and RET-where-you-are is the gesture the binding exists for — the field is prefilled instead). - Verification at merge: 1,832 default + 2,009 CRDT library tests; dired acceptance 25 + 25 CRDT; the frozen m8_1 10 / m8_2 15 / m8_3 32 unchanged, which is the additivity gate for the `read_dir` change; M4 121; required GPU 155; isolated-`XDG_CONFIG_HOME` workspace sweep 3,205 across 93 suites. 15 claims bite-verified. - Canonical `main` is protocol **v20** (`SUPPORTED=[6..=20]`; v16 = `ThemeFacts`, v17 = `FontFacts`, v18 = `StatuslineSegments`, v19 = terminal frames/events, v20 = the GPU initial-target semantic bootstrap family). Bottom-panel Stage 2B-1's in-review schema is v21 (`SUPPORTED=[6..=21]`), but its production daemon deliberately advertises v20: the handshake is server-first, so advertising 21 would make shipped v20 GPU/TUI clients reject before `AttachRequest`. Stage 2B-3 owns compatible production activation. - **Bottom panel Stage 1 (window placement + TUI side windows) LANDED — #155** (`docs/bottom-panel-framing.md` rev 4; merge `e745068`; two review rounds). **No protocol change (still v20).** Arc 7's substrate: pmacs now has Emacs's `display-buffer` + window parameters, and a buffer can be displayed in a fixed-height window pinned to the bottom of the frame that feature code targets **by policy** instead of by stealing the selected window. - `src/window.rs`: `WindowParams { side, fixed_rows, dedicated }` plus implementation-owned `quit_action` / `origin_document` (Lua reads them, `set_params` refuses them); `MIN_WINDOW_OUTER_ROWS = 2`; `Layout::compute(area, fixed)` subtracts fixed children before dividing the remainder by weight, preserving last-flexible-takes-the-remainder, so a tree with no fixed leaves computes byte-identically to before. - **`Layout::compute` has TWO production callers**, and both must feed the same shared `panel_fixed_rows` map: `window_placements` and `src/overlay_paint.rs`'s peer-presence pass, which derives its own text-area `Rect` and never routes through the first. Leaving the second on unfixed geometry paints every peer cursor at the row it would occupy with no panel open. - **The minimum is recursive** (`subtree_min_rows`: horizontal splits sum, vertical splits max). "Two rows at the root" does not give each nested leaf two rows. `interactive_min_rows` is the same recursion over the user's `window.min-height` preference, and applies to drag/keyboard resize ONLY — the layout pass and frame-resize reconciliation use the structural floor, so changing a preference can never invalidate an existing layout. - **Hiding a panel is a durable state transition, not a per-frame effect** (`EditorState::reconcile_panel_layout`): it moves focus out and releases the terminal controller, because the terminal resize path merely returns on zero content without releasing. It runs after attach/resize/display/ close and defensively before input dispatch, terminal sync, and paint. - `FrontendView` gains `panel_capable`, `frame_geometry` (`None` = **unknown**, never the GPU attach request's permanent 24×80 placeholder), and derived `panel_hidden` — each spelled explicitly at every construction site, preserving folding's non-`Default` discipline. - `EditorCore::primary_document_window` is the Q#BP14 projection seam; `display_buffer` is Phase 1 of the display transaction (exact target → side affinity → ordinary reuse, with option-valued height/dedication); the Lua layer owns Phase 2 (activate → hook → reconcile → revalidate → final-focus matrix). - **Optimistic input is gated per WINDOW, not per buffer**: `dispatch_idle_for` returns `false` whenever the acting frontend's active window is a side window. Marking the panel's BUFFER round-trip would be wrong — `round_trip_buffers` is global by `BufferId`, so it would disable optimistic apply for another frontend editing that buffer as its document. - Jump entries are per frontend and carry their origin `WindowId`; a stale **side** origin is SKIPPED, because degrading it to an active-window switch is exactly the duplicate-panel corruption the arc removes. - `pmacs.window.display / display_file / quit / panel / params / set_params / resize / display_target`, plus `builtin/runtime/window.lua` (`window.panel-height`, `window.min-height`, `C-x ^` / `C-x C-^`). Adopters take `display = "current" | "panel"`; **Stage 1 default is `"current"`** and Stage 3 flips it. - The divider is the upper subtree's existing mode-line row — no row added or consumed, `ui.divider` restyles every exposed segment of one boundary, and drag state is `HashMap` so frontends cannot steal each other's gestures. - `open_initial_target` now shares one `resolve_target_buffer` + exact-window install seam with `display_file`, and reasserts into a document window after hooks (a startup hook can now create a panel). - Final gates: 1,817 default + 1,994 CRDT library tests; the new `bottom_panel_stage1_acceptance` 46; kill ring 30; compile 67; M4 121; required GPU 152; initial-target 14 CRDT; all three vterm suites; folding Stage 2 48. All 12 CI checks green at merge. - **Stage 2 (the GPU panel band) is FRAMED; its first two slices have LANDED and its third is open as PR #187** — `docs/bottom-panel-stage2-framing.md` rev 6, four framing review rounds, no open framing items; the rev-5 implementation split was explicitly approved 2026-07-27 and rev 6 records PR #184's server-first compatibility and gate correction. It reserves protocol **v21** and ships as four serial implementation slices: **2A** classified census routing + per-window painter extraction (no wire change, #177), **2B-1** the wire (#184), **2B-2** the daemon projection and epoch machine (implemented but not landed in PR #187), then **2B-3** the GPU band, compatible v21 activation, and the negotiated `panel_capable` flip. Production attachment remains v20 through 2B-2. Parent acceptance 37–55 remains authoritative. Stage 3 is the adopter default flip. **Do not start 2B-3 until PR #187 lands.** Its branch, checkpoints, two review rounds, verification, and exact recovery commands live in `docs/active-work.md`. - **The §1.3 census is CLASSIFIED, not uniformly redirected.** Only the Projection class (#1–#12, #21–#22) routes through `primary_document_window`; focus/input (#13–#15, #23), focus chrome and surface-routed (#16–#19), and focus/session (#20) keep their own authorities. Rerouting them breaks remote-op validation and application, `DispatchIdle`, presence, focused search/menu/completion routing, and terminal bell ownership. - **Bottom panel Stage 2B-1 (the reserved v21 wire) LANDED — #184** (merge `6bee09d`, 2026-07-28, two review rounds plus a gate-found follow-up; all 12 checks green on reviewed head `5539b6e`). It adds no producer, no consumer, and no capability: `panel_capable` is still `false` for every semantic session, so nothing about it is user-visible. What it establishes is durable: - **Schema support and production advertisement are separate facts.** `SUPPORTED` is now `6..=21`; the daemon's unsolicited `Hello` still says 20. This is not a hedge — **the handshake is server-first**, so a shipped v20 frontend rejects a `Hello { protocol_version: 21 }` *before* it can send an `AttachRequest`. Bumping the advertised version is therefore an incompatible act on its own, independent of whether any new message is ever sent. A real-daemon acceptance emulates that exact rejection point and then requires the attachment to reach its initial grid. **2B-3 must ship a compatibility-preserving activation mechanism; it may not simply change the unsolicited `Hello` to 21.** - **One shared grid validator, split along a stated boundary** (`pmacs-protocol/src/wire_grid.rs`). Shared: checked area, the visible-cell bound (262,144), cell count, cursor bounds, glyph legality, wide-continuation topology, the 8 MiB aggregate glyph-byte budget, and the attachment rejection. Terminal-only: the 512 per-axis PTY caps, title/process metadata, selection spans, and the `at_bottom == (scroll_offset == 0)` coupling. Per-axis caps are a `WireGridLimits` **parameter**, not a constant, because a panel does not inherit them — a 4K surface at a small font is legitimately wider than 512 columns, and the *area* bound is what keeps the encoding inside the transport budget. The attachment rejection is deliberately shared: panels render no attachments either, so classifying it terminal-only would let a panel ship a cell no frontend can paint. - **`PanelFramePayload::Absent` is authoritative, and silence is not.** The receiver retains its last valid frame, so a close *or* a hide must send `Absent` explicitly or a stale band stays on screen indefinitely. Validation is likewise atomic — a bad frame is rejected whole and the previous valid frame is retained. - **Two epochs, answering two different questions.** `panel_epoch` is opaque and monotonic per frontend: stable across ordinary frames of one continuously present window/buffer, and moved on buffer replacement, new side-window creation, and every `Absent` → `Present` transition — which is what stops a stale `PanelPointer` from addressing a reopened panel as if it were the old one (Q#BP16). `geometry_epoch` answers a *frontend* declaration and moves whenever the frontend declares new effective cell geometry, **including a font or scale change that leaves `CellSize` identical** — exactly the case daemon-side value dedup cannot see (Q#BP2S1). - `PanelFrame` carries an explicit `buffer_id` (review round 1) and its `focused` bit is presentation and focus-chrome routing only (Q#BP14b) — the *keys* decision remains `DispatchIdle` (Q#BP14a). - The frontend half is `FrontendEvent::{FrontendCellGeometry, PanelResizeRows, PanelPointer}`, gated in both directions, with each extended enum byte-pinned on its own previous final variant so the v6–v20 encodings are provably unchanged. - **A version bump is not done until every ratchet that pins the old version moves.** The full gate — not review — found that the statusline and Vterm Stage 3 ladders still pinned v20 and rejected v21, in both structural and real-headless-probe form. Grep for the outgoing version across `tests/` before calling a bump complete. - **Bottom panel Stage 2B-2 (daemon projection + epoch machine) LANDED — #187** (one review round of five findings on top of the implementation; 12/12 green; 22/22 mutations bite). What it establishes, beyond the feature: - **A durable transition implemented as a per-frame effect is a bug shape, not a style.** Four of the five review findings were one defect: a renderer-side conditional with a durable twin that disagreed with it. Wire-area exhaustion hid the rendered frame but left panel state live; a stale `panel_epoch` could address a reopened same-buffer panel; `NoMessage` cleared statusline segments it should have retained. The fix that generalizes is `presentable_panel_grid` — **one** private derivation behind both the renderer and `reconcile_panel_layout_core`, because two derivations of one predicate is *how* they drift. When touching panel rendering, ask of every conditional: is there a durable twin, and does it agree? - **Ask what the other frontend kind's equivalent does.** The semantic panel terminal missed the pre-child-drain resize its document sibling had; the repro is a 4×20 panel reporting 3×120. The new `sync_semantic_panel_terminal_layout` is disjoint from that sibling *by construction* — one resolves through `primary_document_window`, the other through `side_window_for` — so the SIGWINCH storm the original extraction prevented cannot recur through the new path. - **A panel may legitimately be wider than a PTY.** `>512` columns are legal on the wire (2B-1's `WireGridLimits` parameter), but `snapshot_for_view` refused the band's content rect and the band went `Absent` with `panel_hidden` false. Clamp the *terminal projection*, not the band: the child takes the columns a PTY can have and the remainder is band background. - **Mutation testing cannot reach behaviour never modelled.** All 16 original mutations passed while five real defects stood; one of them even fired, removing an `Absent` the test asserted. Mutations prove assertions bite the code that exists. They say nothing about the assertion never written. - **One durability hole is accepted deliberately:** epoch exhaustion stays a per-frame `Absent`, flagged rather than hidden, because making it durable needs a new "presentation permanently unavailable" reason in `FrontendView` for a state requiring 2^64 presentations in one session. - **dired Stage 2 framing LANDED (document only) — #171** (`docs/dired-stage2-framing.md`, revision 9; seven review rounds). **Approved as a framing; no runtime code and no implementation started.** Load-bearing decisions a reader must not re-derive: - **Reconciliation is order-independent, deliberately.** Reply order is *not* execution order — `AsyncRuntime::tick` drains the bus with `try_recv`, so a worker can finish first and be descheduled before sending. An ordering token was rejected rather than built: no static rule rescues the hazard anyway (rename `dir`→`newdir` racing delete `dir/child.txt` needs opposite orders depending on which ran first), and no production path can produce it. The trigger to revisit is named: the first production caller that fire-and-forgets two interdependent mutations. - **A refused mid-edit kill is already destructive.** `kill_buffer` clears round-trip state and moves windows *before* `BufferRegistry::remove` can return `ConcurrentEdit`, so `editing_in_progress` must be preflighted rather than relied on to refuse cleanly. - **Path-backed buffer names are not full paths.** `get_or_load_buffer` takes the name from the path *as given* and normalizes only the stored path, so a relative open is named `foo.rs`. Rename provenance is path-*equivalence*, not equality. - **URI-keyed stores have uncorrelated writers.** `textDocument/publishDiagnostics` is absorbed unconditionally, and `mark_document_stale` takes no `LspServerId` at all while creating URI keys across three stores. A route purge keyed on request responses cannot cover either. - **Resource-op delete guard framing LANDED (document only) — #186** (`docs/resource-op-delete-guard-framing.md`, revision 5; five review rounds). **Approved as a framing; no runtime code.** It owns the urgent **pre-filesystem refusal** for synchronous `apply_resource_op` — which on `main` today destroys unsaved work — while #171 owns full post-delete lifecycle reconciliation. Carried facts: - The sequence is `stat/no-op -> enumerate and validate -> mutate filesystem -> reconcile`. Validation inspects without removing, so a failed deletion leaves buffers intact and `on_removed` still observes the path already gone. - **`EditorCore::find_buffer_for_path` is the wrong lookup** — it delegates to first-match-only `find_by_path`, and `pmacs.buffer.from_file` creates path-bound buffers with no dedup, so a clean first match can hide a modified second. - **LSP does not promise batch atomicity, and pmacs advertises no `workspace.workspaceEdit` capability at all** — no `documentChanges`, no `resourceOperations`, no `failureHandling`. Recovery is the client's declared choice, and there is no spec default for a client that declares none. Say only that observed pmacs behaviour *resembles* abort-style application. - **`pmacs.fs.remove` has no dirty check of its own** and neither lane adds one. After both land the guards sit one layer above it. Latent — zero production callers — but "both lanes guard deletion" reads as the primitive being guarded, and it is not. - **GPU initial target LANDED — #148** (`docs/gpu-initial-target-framing.md` rev 3; merge `0dd16a5`; two review rounds). `pmacs --gpu [--socket NAME|PATH] FILE` transports exact Unix path bytes plus launcher cwd to the managed GPU client. Protocol v20 adds a semantic-session `SessionBootstrapRequest` after `AttachRequest` and an appended `InitialTargetResult` readiness barrier; v6–v19 wire encodings stay pinned. The daemon resolves the path lexically, deduplicates or loads/creates it in the authenticated frontend's view, runs the established load/switch hooks, upgrades the buffer for CRDT, and publishes every target-side CRDT upgrade to existing grid replicas before readiness. Semantic replicas receive a publication only when displaying that buffer, so a second target launch cannot switch an existing GPU window; one dead peer cannot fail the new session. Failed bootstrap writes a bounded result, shuts down the socket, removes provisional state, and restores the ambient active frontend. Any stale event from an uninstalled session is dropped before state access. Existing no-target managed launch, direct attach, TUI, and legacy protocol behavior remain intact. Folding Stage 2 integration: fold projection at attach is selected from the same negotiated `semantic_render` bit the target bootstrap uses (grid collapses, semantic/GPU stays source-line pending Folding Stage 3). Final gates: 1,815 default + 1,992 CRDT library tests; target + invocation gates 14/14 CRDT each; Folding Stage 2 48 CRDT; M4 121; required GPU 152; Vterm Stage 3 5 default + 7 CRDT; isolated-config workspace sweep 3,334 across 88 suites; two concurrent real Wayland/Vulkan GPU windows stayed on distinct target buffers after the second attach. All 12 CI checks passed. - **Folding Stage 1 (headless fold engine) LANDED — #142** (`docs/folding-framing.md` rev 5; merge `c49a8c7`; three review rounds, round 3 clean). Arc 6's engine — instance-side and headless; **no frontend renders a collapse yet** (that is Stage 2). No protocol bump. - `src/fold.rs`: a per-buffer `FoldStore` of byte ranges attached as a translating/dropping `View` (the `BufferStyleSpanTranslator` pattern — it translates strictly-inside edits and DROPS boundary-crossers, provenance-blind); `FoldRegistry`/`SharedFoldRegistry` = `Rc>, ViewId}>>>` (the SyntaxRegistry per-buffer model), held on both `EditorCore` (`src/editor_core.rs:223`) and `EditorState` (`src/editor.rs:110`). Containment is **start-exclusive, end-inclusive `(start, end]`**; the stored range is `[end of head line, end of last hidden line]` (NOT the `ByteRange` struct doc's `[start,end)`). - Structural source: nearest enclosing block-like node ≥2 source lines → resolve introducer↔body → **derived head line** (the line immediately above the first hidden line, so wrapped signatures / `where` clauses stay visible) → **closer-aware tail** (a closing-delimiter line stays visible, e.g. `} else {`). Stale/absent parse tree refuses. - The six `EditorCore` edit primitives call `unfold_before_point_edit` first (command-path pre-edit unfold, keyed on the active frontend's point). Interactive Lua-command unfold (yank/query-replace/comment) is a Stage 2 obligation; CRDT-origin unfold is Stage 3. - `src/lua_bindings/fold.rs` (`install_fold`): `pmacs.fold.*` data API (explicit buffer, no ambient resolution, matching #127) + interactive commands on the **Emacs hideshow `C-c @` prefix set**; `builtin/runtime/fold.lua`. - `src/semantic_render.rs`: `fold_state_msg` PRODUCES `FoldState` (semantic/GPU sessions) — authoritative-empty, diff-suppressed, per-session baseline reset on `BufferSnapshot` (the #120 stale-mirror trap class; the GPU fold-mirror clear-on-snapshot is a named Stage 3 obligation). - Durable lesson (round 2): after wiring a cleanup into a production hook, PIN IT THROUGH THE REAL PATH — a direct-call unit test misses the wiring (falsify by revert). - **Stage 2 (grid/daemon collapse) LANDED — #149** (merge `6ed4fe9`; five review rounds; `docs/folding-stage2-framing.md` rev 4). Its load-bearing reframe: the TUI had **no non-identity source-line↔display-row map** (`view_top + row` was baked into ~13 sites), so Stage 2's spine is `src/fold_view.rs`'s `VisibleLineMap` — derived from the fold store plus a window's line offsets, never stored — that the render loop, gutter, diagnostics, caret, selection, peer presence, viewport/scroll/motion, and the mode-line indicator all route through, plus the interactive-Lua unfold widening. Threaded as `Option<&'a VisibleLineMap>` on a lifetime-bearing `Viewport<'a>` that stays `Copy`. Design points the review rounds forced, each a trap for Stage 3: - the map's unit is a **merged hidden component** (overlapping *or adjacent* intervals unioned, keeping the earliest visible head), not a fold — folds may cross, and an inner/later fold's own head can be hidden; - instances are **per rendered window** and **per command/event operation**, never per frame; a command's map follows the operation's TARGET window (a wheel event names a pane without activating it); - fold projection is **per-frontend** (`FrontendView.fold_projection`, set at attach from the negotiated `semantic_render` bit) — shared `EditorCore` motion would otherwise make a simultaneous unfolded GPU session's cursor skip lines it still displays; - a hidden cursor normalizes by **position**, not row, and `set_view_top` clamps in the setter rather than being repaired at render time; - the interactive-Lua unfold keys on the **post-intercept** edit site — a managed buffer intercept may legally relocate the op. No protocol bump. **Stage 3 (GPU) is next and has no framing yet**; its named obligations are GPU collapse at TUI parity, caret/hit-test fold-awareness, the `BufferSnapshot` **fold-mirror clear** (parent R2-4 — the #120 trap class), CRDT-origin / GPU-optimistic interactive unfold (parent R2-3), and flipping `FrontendView.fold_projection` to `true` for semantic frontends. - **One-command GPU invocation LANDED — #141** (`docs/gpu-invocation-framing.md` rev 6; merge `63fbc66`; two implementation reviews). The additive public path is `pmacs --gpu [--socket NAME|PATH]`; bare `pmacs [FILE]` remains the TUI. Root owns the CRDT gate, socket resolution, sibling-regular-file GPU discovery/PATH fallback, and GPU outcome. The separate `pmacs-gpu` binary owns connect-or-start, a five-second / 50-ms retry window, pre-winit event buffering, daemon process-group/stdin/stdout/stderr isolation, and named child reaping with explicit ownership handoff. Direct `pmacs-gpu --attach RAW_PATH` remains strict, is documented as advanced, and never auto-starts. No protocol change. The initial macOS/LuaJIT CI run exceeded an unrelated outline performance threshold (147 ms / 100 ms); the complete failed-job rerun passed all twelve checks before merge. - **Config registry LANDED — #127** (`docs/config-registry-framing.md` rev 3; merge `2e37c04`; two review rounds). `pmacs.config` is the typed, introspectable options registry the backlog ranked first, and it closes the "config-registry-blocked" deferrals below. It was built as a PARALLEL LANE alongside vterm in a sibling worktree; the files were assigned per-lane up front and the rebase had zero conflicts. - **Third registry** beside `CommandRegistry`/`HookRegistry` (`src/config_registry.rs`), same R42/R50/duplicate-rejection/ `SourceLocation` vocabulary; Lua surface in `src/lua_bindings/config.rs`. **No protocol change (still v18) and ZERO changes to `src/editor.rs`.** - **An override is ALWAYS stored**, even when equal to the value it shadows; only `value_epoch` and listener dispatch key on effective change. The "equal-value set is a no-op" reading silently voids a buffer-local pin: nothing is stored, and a later global `set` flips the very buffer the user pinned. - **Two scopes: global and buffer-local.** `get(name, buf)` resolves local → global → default; **`get(name)` resolves the GLOBAL CHAIN ONLY** and never consults an ambient buffer. Per-language and per-project are *patterns* (a hook calling `set_local`), not scopes the registry knows about. Mode keymaps now resolve through #129, but `pmacs.config` deliberately remains global + buffer-local. - Buffer-locals live in a registry side table purged at `after_buffer_removed`, beside the keymap purge. - Listeners: commit → snapshot → **drop the borrow** → re-enter Lua; a raising listener is logged without blocking the rest or rolling back; a depth bound turns a cycle into a pointed error. **Explicit dispose only** — there is no `MetaMethod::Gc` anywhere in the codebase, and GC timing differs between the two Lua backends. - `StartupOnly` freezes off the existing `InitCompleteFlag` at write time (which is why no `editor.rs` call was needed). In `--lib` builds `set_init_complete` never runs, so a post-freeze test must flip the flag explicitly or it passes vacuously. - Adopters own their own `define`, so `SourceLocation` names the owning module: `editing.auto-pair` (pair.lua, read against the typed edit's SOURCE buffer), `editing.trim-on-save` (editops.lua, read against the buffer being saved), `autosave.interval-ms` (autosave.lua, re-read per tick). **The migration wrappers keep their legacy coercion** — the registry is strict, the legacy setters stay lenient (`trim_on_save("yes")`, `interval_ms(1500.7)`). - `M-x describe-setting` renders into `*help*`. - **Mode system wiring LANDED — #129** (`docs/mode-system-wiring-framing.md`; merge `b4b925d`; one review round). The existing mode-keymap substrate is now live without a protocol change. - `Buffer.major_mode: Option` owns the single major mode. The detected language name initializes it once on `buffer.after-load`, before grammar gating, so server-only languages work; switches never rewrite it. Explicit overrides and clears survive switches. A future reload that fires after-load re-detects, and explicit mode state is not session-persisted. - Dispatch borrows the zero-or-one mode through `Option<&str>::as_slice()` and `&[&str]`: no hot-path mode allocation. Resolution remains buffer-local → mode → global, and registry/keymap borrows end before Lua command invocation. - Lua surfaces: `pmacs.buffer.major_mode` / `set_major_mode` and `pmacs.editor.active_modes`. `pmacs.describe.key`, `pmacs.help.show_key`, and followed percent-encoded `@mode:` links use the same effective context; `pmacs.keymap.lookup` remains raw-global. - The built-in `mode` statusline provider reads `ctx.buffer`, so passive splits render their own mode. Real-daemon acceptance covers all ten framing criteria across both Lua backends and Linux/macOS CI. - **Modeline language detection LANDED — #132** (`docs/modeline-detection-framing.md` rev 2; merge `1dd47fc`). Fresh loads scan bounded Emacs `-*- mode: ... -*-` and Vim/Vi `ft=` / `filetype=` modelines without evaluating file content, normalize common editor aliases, and give explicit modelines precedence over inferred language. - `builtin/runtime/syntax.lua` owns one per-buffer fresh-load decision: modeline → bundled grammar extension → LSP filetype extension → exact filename → shebang. Syntax, initial major mode, pairing, comments, and LSP all reuse that pin; LSP retains its independent backing-path guard. - Editing a modeline or shebang does not switch an attached parser or make language-aware consumers diverge. Close/reopen re-evaluates changed file metadata. Explicit post-load major-mode overrides remain independent. - Bounded valid unknown names remain passive major modes without starting an unavailable parser or server. All thirteen framing criteria are covered on LuaJIT and Lua 5.4. No Rust or protocol surface changed; protocol stays v18. - **Syntax-highlight / language-detection side-quest (#114–#118) LANDED** — a one-shot arc built in sibling worktrees off main while the user's themes lane (`theme-faces`) ran concurrently in the shared checkout. All merged. What shipped: - **Grammars** (`crate::syntax::BUILTIN_LANGUAGES`): every LSP-configured language now has one — cuda, bash, dockerfile (via the ABI-current `tree-sitter-containerfile`, NOT the dead `tree-sitter-dockerfile` which pins `tree-sitter ^0.20`), make, cmake, python, go, javascript (+jsx), typescript (+tsx), toml, zig. - **Detection chain and pin** (`builtin/runtime/syntax.lua`): modeline → grammar extension → LSP filetype map → filename → shebang. User-extensible Lua surfaces include `pmacs.parse.modeline_aliases`, `.shebangs`, `.filenames`, `language_from_modeline`, `language_from_shebang`, `language_from_filename`, and the pinned `buffer_language`. `builtin/runtime/lsp.lua` delegates to that shared decision after enforcing its backing-path requirement. Grammar name MUST equal the `pmacs.lsp.config.` key. A buffer keeps its pinned language across edits/switches; close/reopen performs a fresh bounded inference. - **LSP configs added**: dockerfile (`docker-langserver --stdio`), cmake (`cmake-language-server`, config via `init_options.buildDirectory="build"` — it does NOT pull `workspace/configuration`). Make has no server. - **Substrate**: `LanguageEntry.highlights_query` and `.locals_query` are `&[&'static str]` fragments joined base-first (cuda over c/cpp; ts over js/jsx). Since locals-query processing #134, settle compiles the grammar's `LOCALS_QUERY`, resolves Tree-sitter's scope/definition/value/ reference conventions into sorted `LocalFacts`, and stores them beside each layer's tree/query. Work runs once per fresh bundle and only when the highlight query asks about `local`; viewport rendering remains bounded. Both TUI and semantic/GPU producers evaluate `#is?`/`#is-not? local` through the shared capture walk. Non-shadowed JS/TS builtins are restored; shadowed definitions/references keep ordinary variable styling. - **Multi-language injections (#122) LANDED** — the direct continuation of the #114–#118 highlight arc; four review rounds, framing `docs/multi-language-injections-framing.md` (Q#IJ1–IJ11). A buffer can now hold more than one language: `ParseTreeBundle` holds `Vec` (root + injected children, depth-ascending, installed atomically so the existing `StyleGate` + highlight-cache Arc gates still work). The parse worker builds child trees off the static `BUILTIN_LANGUAGES` table (lazy load preserved) via `set_included_ranges` — child node offsets are ABSOLUTE, so injected spans are buffer-coordinate-native; settle resolves each layer's highlight query (`SyntaxRegistry::resolve_layer_queries`). First consumers: markdown fenced code + `markdown_inline` (retires the M9.7 block-only floor). New substrate: `LanguageEntry.injections_query`; `default_injection_aliases` + `SyntaxRegistry::injection_alias_snapshot` (case-folded fence names, Lua-extensible via `pmacs.parse.injection_aliases`, snapshotted into `ParseRequest` so the worker never touches the `Rc` registry or Lua); `ParseTreeBundle.injection_capped` (the 4096-layer backstop, surfaced once/buffer via `pmacs.error` at settle); `compute_highlight_spans_for(query, tree, source, local_facts, range)` (per-layer); the wire `flatten_layer_spans` event-sweep → DISJOINT effective spans (deeper / later-sibling / narrower wins, keyed by `(layer_index, capture_order)`); GPU `spans_from_segments` + `source_color_at` fold. Two findings to keep: injection ranges exclude only NAMED children (anonymous tokens ARE the injected text — excluding them shreds a block `inline` node; matches tree-sitter-md's own splitter), and the wire flattener runs over the WHOLE buffer via the file-style summary, so it must be an event sweep, not O(spans²). - **JSON + YAML grammars and language servers (#123) LANDED** — bundled ABI-current `tree-sitter-json` / `tree-sitter-yaml` cover `.json`, `.yaml`, and `.yml`; the existing injection engine now highlights YAML frontmatter and JSON/YAML fences. Default external LSP configs are the pinned `vscode-json-language-server` provider and `yaml-language-server`; configured settings are pushed after `initialized`, which also supports push-model servers. The fake-server delivery proof and PATH-gated live JSON/YAML provider smokes cover the configuration contract. `.jsonc` / `.json5` remain a deliberate follow-up because the JSON grammar is strict. - **Compile-mode (Arc 5 stage 1, #113) LANDED** (2026-07-14, 7 rounds; framing `docs/compile-mode-framing.md` rev 13). `compile.run` streams `/bin/sh -c "exec 2>&1; "` into an intercept-read-only `*compilation*` buffer via a Lua ANSI parser; once-per-newline error rules; unified `error.next`/`error.previous` (M-g n/p, `` C-x ` ``, M-!). Substrate other code can use: `ProcessSpec.stdin/group` (group lifecycle: reap ledger, in-drain enforcement, cancellable poll readers), `buf:revision()`, jump_back fires `buffer.after-switch`, `pmacs.errors.claim`, `AnsiParser::finish()` (observable reset), and the style-overlay stack: buffer-attached `BufferStyleSpanTranslator` (once-per-edit, fragment-preserving), render-only window overlays with identity-deduped `Window::ensure_overlay` + `clone_for_split`, idempotent atomic `handle:dispose()`. - **Editing-conveniences pack (editops, #111) landed** (framing `docs/editing-conveniences-framing.md` rev 6). goto-line, case ops, transpose, zap-to-char, line move/duplicate/join, region sort/reverse/dedupe, delete-trailing-whitespace + opt-in `pmacs.editops.trim_on_save`. Substrate: `pmacs.killring.kill_range` / `break_chain([fid])` / `arm_kill_prompt`+`commit_kill_prompt` (marker lifecycle), and the origin-guard pattern for chain-sensitive minibuffer commands. - **Auto-pairing (#110) landed — Arc 2 COMPLETE** (framing `docs/auto-pairing-framing.md` rev 6). `BUILTIN_PAIR_CHARS` in pmacs-protocol leave both frontends' optimistic classifiers; `builtin/runtime/pair.lua` loads BEFORE lsp.lua (first-didChange ordering contract); one-shot typed-edit provenance via `pmacs.editor.take_typed_edit()` (buffer-revision postcondition, Q#AP9). Substrate: `buf:path()`, `pmacs.lsp.buffer_language(buf)`, `PMACS_FAKE_LSP_CHANGE_SINK`, `TestDaemon::spawn_with_config`. - **Themes (Arc 4) stages 1–3 LANDED; Arc 4 COMPLETE ON `main`.** - Stage 1 (#120, `docs/theme-faces-framing.md` rev 9): named UI faces as reserved `ui`/`ui.*` theme entries; transactional split syntax/face epochs; protocol-v16 `ThemeFacts`; snapshot/baseline symmetry; store-sourced diagnostic-count freeze. - Stage 2 (#124, `docs/gpu-set-font-framing.md` rev 5): `pmacs.gpu.set_font` and authoritative protocol-v17 `FontFacts`; frontend-local family resolution, live font reload/reflow, and visual-run caret geometry. - Stage 3 (#125, `statusline-segments`, `docs/statusline-segments-framing.md` rev 3): composable strict `pmacs.statusline` providers; borrow-released per-window evaluation with failure latches; legacy-preserving TUI composition; a pure built-in LSP provider; dynamic modeline faces; protocol-v18 `StatuslineSegments`; authoritative-empty/snapshot symmetry; and atomic GPU validation, face resolution, shaping, clipping, and cache invalidation. Acceptance 1-27 is implemented. Final gates: Clippy clean; 1,619 default + 1,793 CRDT library tests; 7 default + 8 CRDT feature acceptance; 114 M4; 109 required GPU; one-invocation workspace sweep 2,718 passed across 78 suites (19 ignored, `basedpyright` filtered); `git diff --check` clean. Stage 3 landed as #125 and completed Arc 4 on `main`. - **Vterm Stage 1 terminal core LANDED ON `main` — #126** (`docs/vterm-framing.md` rev 5; merge `643d1e1`). - Implementation commits: `bbc1f33` (Stage 1), `962944b` (Darwin signal normalization), first-review fixes `f0a235f`, `28f2e6c`, `bf972a7`, and second-review hardening `9797ada`; reviewed feature head `fc4e0ce` merged through PR #126, . - `AnsiParserProfile::{LineOriented, FullScreen}` preserves compile/REPL behavior while terminal PTYs emit the full cursor/mode/device operation set. `src/terminal/{screen,input,session}.rs` owns the state machine, encoders, and lifecycle registry. - Public session seam: owned strict `TerminalSpec`; owned `TerminalSnapshot`; `TerminalProcessState`; and `SharedTerminalManager = Rc>` with `open/is_terminal/process_id/snapshot/tick/send/resize/terminate/prune/ shutdown`. Stage 1 snapshots are context-free; Stage 2 adds per-view state without a second screen. - `EditorState` tick order is supervisor → terminal-owned PID drain/prune → `process.after-tick`. Terminal IDs are not exposed through `pmacs.process`; ordinary Lua/LSP/MCP ownership is unchanged. Terminal identity buffers are pathless, clean, empty, round-trip, and guarded read-only at every rope/CRDT/history mutation boundary. - Acceptance 1–14 is mapped in the framing. The real PTY bite splits ESC/CSI writes, observes alternate-screen cursor addressing, blocks and resumes through raw `send`, restores the main screen, and pins final output before exact PID/outcome annotation. One-row annotation visibility, TERM-ignoring shutdown, spawn rollback, buffer-kill prune, and immutable empty CRDT bootstrap are pinned. - Review round 1 added typed IND/NEL/RI with margin-correct screen behavior, defaults absent `TERM` to `xterm-256color`, makes shutdown liveness acceptance portable with `kill(pid, 0)`, and preserves custom tab stops on resize. Review round 2 rejects C0/C1 controls before they enter screen cells, preserves the released button code in SGR mouse reports, removes dead screen paths, and clears stale round-trip state during prune. Stage 2 now uniquifies default terminal buffer names transactionally. - Exact CUU/CUD and out-of-range DECSTBM clamping, combining across controls, xterm alternate-screen details, legacy non-SGR mouse, printable ASCII and CSI-dispatch allocation fast paths, and scrollback-cap naming are explicit post-arc deferrals in the framing. - Final from-start rerun after review round 2: Clippy clean; 1,661 default + 1,837 CRDT library tests (3 ignored each); 9 default + 10 CRDT vterm acceptance; M4 114 passed (3 ignored, 1 filtered); required GPU 109; workspace 2,769 passed across 79 suites (19 ignored, 1 filtered); diff check clean. `scripts/bite HEAD^ src/terminal/screen.rs --test vterm_stage1_acceptance terminal_cells_reject_child_control_characters` is a clean behavioral bite. The parser dispatch has its independent clean behavioral bite; the original `main`/crate-root bite remains explicitly weaker compile-time API evidence. - **Stage 3 GPU/protocol LANDED ON `main` — #135** (merge `cac4961`; `docs/vterm-framing.md` Revision 9, criteria 28–37). Protocol **v19**: `InstanceMessage::TerminalFrame` (discriminant 26, daemon-gated) plus `FrontendEvent::TerminalResize` (11) and `TerminalPointer` (12), both frontend-gated — the first bump gating in BOTH directions. `SUPPORTED=[6..=19]`. - `pmacs-protocol/src/terminal.rs` now owns the shared terminal bounds, `TerminalProcessState`, `TerminalSelectionSpan`, and the single structural policy `TerminalFrame::validate`; `src/terminal/*` re-exports them so no duplicate type exists. `unicode-width` is a workspace dependency so the screen and the validator measure glyph columns identically. `MAX_TERMINAL_FRAME_GLYPH_BYTES = 8 MiB` bounds the payload instead of widening the transport cap; the measured maximum legal frame encodes to 13,437,863 bytes under the unchanged 16 MiB `MAX_FRAME_BYTES`. Over-bound snapshots are rejected, never truncated or silently chunked. - **The `Viewport` gate keys on the AUTHENTICATED SOURCE'S ACTIVE BUFFER, not the buffer the message names.** `Viewport` also aligns the window to the buffer it declares, so a stale document viewport in flight when a command opens a terminal drags the frontend back off it - the terminal then never paints, with no error anywhere. The weaker "is the declared buffer a terminal" reading looks right and fails exactly this way. - Suppression compares the COMPLETE ordered payload, never `screen_generation`: scroll, selection, viewport, and process state all change without advancing it. - GPU: `pmacs-gpu/src/terminal.rs` is a pure cell-space paint planner (testable without a GPU); the renderer builds one shaped buffer per text run so a wide/cluster advance can never choose the next column's origin. `pmacs-gpu --headless-probe` drives the real attach client without winit (`attach::connect_with_sink`), which is how criterion 37 gets one real daemon + real PTY + real wgpu path. - #135 integrated canonical `main` after #137 landed. The one code conflict joined `TAB_STOP_COLUMNS` with the terminal imports in `pmacs-gpu/src/main.rs`; terminal geometry remains fixed-cell and never consumes the document tab-stop projection. - Final post-integration gates: strict Clippy; 1,768 default + 1,944 CRDT library tests; Vterm Stages 1/2/3 at 9/10, 4/4, and 5/7 default/CRDT; statusline 7/8; tab-width 2/2; M4 121; required GPU 139; workspace 2,946 passed across 84 suites; formatting and diff check clean. The first macOS/LuaJIT CI run timed out waiting for `VTERM_ALT_READY` in the Stage 2 real-TUI smoke; the complete failed-job rerun passed all 12 checks. - **Stage 2 TUI LANDED ON `main` — #130** (merge `86fc1bc`; `docs/vterm-framing.md` Revision 7, criteria 15–27). `TerminalViewKey` keys per-frontend/window projection state over one shared process/screen; logical row anchors retain scroll/selection through reflow. One authenticated frontend controls at most one session, with atomic replacement and release on focus/switch/kill/detach. - The strict `pmacs.terminal` Lua surface owns open/state/view/send/terminate and context-implicit scroll/copy commands; the latter error unless the invoking frontend's active window is a terminal. Fixed `C-c` is the per-frontend terminal escape: only its next key reaches terminal-local editor bindings, while unescaped bound keys pass through to the child. `C-c C-c` sends one literal interrupt. Copy drains through the acting frontend's clipboard path; active BELs drain once locally and per daemon frontend, while historical/passive bells are baseline-suppressed. - TUI composition paints owned terminal cells/styles only inside each window's content rectangle, suppresses document overlays, and keeps sibling splits independent. Daemon key/mouse/paste/focus/resize/detach routing uses the authenticated connection source rather than client-claimed IDs. `builtin/runtime/terminal.lua` provides the terminal command, view commands, and pure `ui.modeline.terminal` process/scroll segment. - `tests/vterm_stage2_acceptance.rs` maps Lua transactionality, shared-view isolation, clipboard/modeline behavior, and a hermetic real `/bin/sh` TUI PTY smoke. Stage 2 changed no wire schema or GPU renderer; protocol remained v18 until Stage 3. - PR #130 review round 1 (`8702791`) aligned dispatch with the approved escape-prefix contract, closed the non-terminal Lua error path, made controller replacement atomic, retained zero-area view anchors, removed duplicate detach work, and replaced per-view deep scrollback clones with borrowed live/published row projections. Focused child-input coverage pins both unescaped bound-key passthrough and `C-c C-c`. - PR #130 review round 2 (`b9a7e40`) clamps anchors into the first surviving cell when eviction cuts through a wrapped logical line, prevents ambient `active_frontend` from minting interactive Lua authority, names malformed explicit-context fields, restores dispatcher rationale, and removes owned cell snapshots from terminal mouse routing. The framing now records the transient v18 semantic-controller boundary and bracketed-paste injection deferral. - Current-main integration (`3f0252f`) preserved per-frontend terminal dispatch while applying the landed mode-scoped keymap, and exposed the `mode`, `terminal`, and `lsp` statusline providers together. PR #130 merged at `86fc1bc`. - Final integrated gate: `cargo fmt --check`; strict workspace Clippy; 1,753 default + 1,929 CRDT library tests (3 ignored each); mode-system acceptance 1 default + 1 CRDT; Stage 1 acceptance 9 default + 10 CRDT; Stage 2 acceptance 4 default + 4 CRDT; statusline acceptance 7 default + 8 CRDT; M4 114 passed (3 ignored, 1 filtered); required GPU 109; workspace 2,882 passed across 82 suites (19 ignored, 1 filtered); `git diff --check` clean. - **Tab-width rendering parity LANDED — #137** (merge `2625ec7`; `docs/tab-width-parity-framing.md` rev 2). Source tabs remain one byte while every buffer renderer follows the shared fixed `pmacs_protocol::TAB_STOP_COLUMNS = 8`. - `src/display_width.rs` owns allocation-free Unicode/tab-aware byte-to-column accounting for plain text, syntax, diagnostics, completion anchors, buffer-style overlays, and search washes. - The GPU rich-chunk projection expands source/adornment tabs before cosmic-text shaping and retains first-class source-tab provenance. Carets, hits, selections, peer washes, and diagnostic geometry share the same source/projected boundary rules, including a soft wrap inside one expanded tab. - GPU minimap widths use the same tab/Unicode rule and refresh in the accepted text-edit transaction. No config, wire shape, negotiation, or protocol version changed. Local gates: 1,763 default + 1,939 CRDT + 1,763 Lua 5.4 library tests; 2 focused acceptance; M4 121; required GPU 119; workspace 2,911 across 83 suites; strict Clippy and diff check clean. - This closes the standing "**tab width is a rendering-parity bug, NOT a config gap**" deferral in §5: one shared constant now drives every renderer. Terminal cells are deliberately OUTSIDE it — a terminal's columns come from the child, so `pmacs-gpu`'s terminal geometry uses the monospace advance and never `TAB_STOP_COLUMNS`. - **PARKED: kill-ring browser + persistence.** Revision 2 framing is preserved on branch `kill-ring-browser`, but its `0efb5cd` scout is stale and must be repeated before implementation. No PR or implementation is active. - Roadmap: `docs/roadmap-2026-07.md` (ranked arcs). Position: - **Arc 1 (LSP utility surface) COMPLETE** — completion popup (#92/#93), panels/references/outline/hover (#94–#96), plus hardening follow-ups (#102, #105, #106). - **Arc 2 (editing table stakes) COMPLETE** — query-replace (#97), kill ring + `M-y` (#103/#105/#106), comment-toggle (#107), auto-indent (#109), auto-pairing (#110). - **Arc 3 (persistence) COMPLETE** — saveplace/recentf (#98), desktop-save (#99), autosave/crash-recovery (#100), save-clobber fix (#101). - **Arc 4 (themes + extensibility) COMPLETE** — named UI faces (#120), live GPU font preferences (#124), statusline providers (#125). - **Arc 5 terminal stage COMPLETE** — compile mode (#113), Vterm terminal core (#126), TUI frontend (#130), and protocol/GPU Stage 3 (#135) landed. - **Config registry COMPLETE (#127)** — not a numbered arc; it was the cross-cutting substrate ranked first on `docs/side-quest-backlog.md`'s north star, and it unblocks the editing/indent/comment items that were config-blocked. - **Mode system wiring COMPLETE (#129)** — major-mode keymaps, introspection, lifecycle initialization, and statusline display shipped. - **Locals-query processing COMPLETE — #134** — grammar locals metadata, lexical resolution, settled per-layer facts, shared TUI/GPU local-predicate filtering, and a registry-wide locals-query invariant shipped without a protocol change. - **Arc 6 (folding) Stages 1 and 2 LANDED — #142 and #149** — the headless fold engine (store, structural source, Lua `C-c @` surface, command-path unfold, `FoldState` production), then the grid/daemon collapse (the `VisibleLineMap` spine, fold-aware gutter/diagnostics/caret/selection/ presence/viewport/motion, and the interactive unfold widening). **Stage 3 (GPU) is next**, unframed. - **Web grammars HTML+CSS LANDED — #146**, and **LaTeX Stage 1 — #144** with its inline-math parent framing **#145**. - **Arc 7 (bottom panel) Stage 1 LANDED — #155** — window placement, window parameters, TUI side windows, the divider, and the adopter `display` opt-in. **Stage 2 (the GPU band) is next and needs its own re-framing**; Stage 3 is the default flip. DAP was parked awaiting exactly this arc's Stage 1 and can now re-baseline its touch census. - Remaining ranked arcs: 6 folding Stage 3, 7 bottom-panel Stages 2–3, DAP, 8 GPU splits, plus the `.ipynb` arc (its JSON-grammar prerequisite shipped in #123). - **GPU terminal input LANDED — #166** (`main` @ `b889873`; `docs/gpu-terminal-input-framing.md` rev 2; one review round). The dispatcher applied **both** terminal-layout syncs to **every** attached frontend each tick. A semantic session satisfies both conditions — a `term_sizes` entry from `AttachRequest` *and* a terminal declaration — so its PTY was resized twice per tick forever: the grid arm installed the TUI placement size, the semantic arm the declared content rectangle, each arm's `old_size == size` guard seeing only what the other had just written. The child took a `SIGWINCH` storm at tick cadence, which made typing into a GPU terminal impossible while output kept flowing. TUI was structurally unaffected. - `EditorInstance::sync_terminal_layout` is split into `sync_terminal_controller_liveness` (frontend-kind **neutral**: panel reconcile + release of a controller whose window moved away — reads only views/windows/controller, never a grid size) and `sync_terminal_grid_geometry` (**grid only**: TUI placement + resize). `sync_terminal_layout` survives as the composition, so `editor::run` and `LOCAL` are byte-identical. - `daemon::sync_terminal_layouts_for_tick` is the extracted loop body: liveness for every frontend once per tick, then **exactly one** geometry arm keyed on `semantic_states` membership — the same fact session establishment uses, so the arms cannot both fire. - **The trap, kept in a comment:** the release on a missing `window_placements` entry reads like liveness and is grid geometry. A semantic frontend has no placement entry at all, so moving it into the neutral half would release a GPU controller every tick. - Why not the one-line guard: the grid arm was also the **only** per-tick controller-liveness release a semantic frontend got, and `sync_semantic_terminal_layout` cannot take it over — the buffer-follow snapshot clears the viewport declaration, so that arm stops running in exactly the switch-away case that needs the release. - No protocol change (v20). Gates: 1,829 default + 2,006 CRDT library tests; vterm Stage 1/2/3 10/6/9 CRDT; bottom-panel 46; M4 121; required GPU 155; isolated-config workspace sweep 3,177 across 92 suites. - **Known gap, its own lane:** CI never enables `crdt`, so the Stage 3 real-path acceptance (including `a37`) is not compiled there. #166's unit pins are not `crdt`-gated and do run. See `docs/active-work.md`. ## 2. How we work (the part that must not drift) The user is expert and reviews deeply — they falsify framings and find real bugs in round after round. The cadence that has worked for ~40 PRs: 1. **Scout ground truth** in the code before proposing anything. 2. **Write a framing doc** — `docs/-framing.md`, numbered decisions (`Q#XY1…`), explicit "Ground truth", "Bets", "Deferred (named)", and an acceptance-test list. Present it and **wait for explicit approval** ("Go for it" / "Ready to roll"). Expect 1–3 rounds of findings first; revise the doc, don't argue. 3. **Branch off main** (one feature = one branch = one PR). Commit the framing as the first commit. 4. Implement. **Every reviewer finding gets a bite-verified fix** — a test that fails without the fix. Watch for vacuously-passing tests. 5. Run the full gate suite (§3). Open the PR with `gh`. 6. The user replies with "Findings" lists on the PR rounds too. Same discipline. They say when to merge — **never merge unprompted**. 7. After merge: update this handoff + your memory. Commit/PR conventions: commit messages via `git commit -F ` (no inline backticks through the shell). **Authorship trailers and PR attributions must be truthful:** do not add a Claude co-author trailer or Claude Code attribution unless Claude actually contributed. Clippy runs as its own step, never `&&`-chained. ## 3. Gate suite (all green before any PR) ``` cargo fmt --check cargo clippy --workspace --all-targets -- -D warnings # own step cargo test --lib # ~1500 cargo test --lib --features crdt # ~1672 cargo test --test cargo test --test m4_acceptance -- --skip basedpyright PMACS_REQUIRE_GPU=1 cargo test -p pmacs-gpu # 58 cargo test --workspace -- --skip basedpyright # full sweep git diff --check ``` Machine-specific caveats — re-verify on a machine you haven't used before trusting them: - **basedpyright**: the DESKTOP's local binary is broken and HANGS the `m4_5_basedpyright` tests — hence the `--skip` there. The LAPTOP has a working basedpyright 1.39.9 (verified 2026-07-10: the m4_5 test passes in 0.18s), so the skip is droppable on the laptop. - **GPU on the laptop**: AMD Radeon 780M (RADV) — native Vulkan, `PMACS_REQUIRE_GPU=1` works without lavapipe. - **Flaky-under-load tests — rerun isolated before treating a sweep failure as a regression.** The m8 daemon tests and the m6 process/PTY tests (`m6_1_pty_mode_lifecycle_started_then_exited`, `m6_8_supervisor_reaps_all_children_across_cycles`) are timing-based; `editor::composition_overhead_under_ten_percent` is a render-ratio microbenchmark that fails ~1/3 even isolated single-threaded (already `cfg!(macos)`-disabled). Vterm Stage 3's merge CI saw one macOS timeout in `real_tui_terminal_smoke_restores_host_after_output_input_resize_scroll_copy_and_bell`; the complete failed-job rerun passed. The required-GPU gate also failed once in `headless_diag_face_recolors_band_counter_despite_unchanged_text`, then passed both an isolated single-thread rerun and the full 139-test rerun. A lone timing failure → rerun the test alone (`-- --test-threads=1`) before investigating. Run the workspace sweep as ONE `cargo test` invocation piped to a full log — a double invocation + `grep -c "test result: ok"` can mask real failures with a misleading `0`. - **GPU tests** need a Vulkan device. `PMACS_REQUIRE_GPU=1` makes absence a hard failure instead of a silent skip. Headless option: lavapipe (see `docs/repository-audit-2026-07-03.md` for the CI harness how-to). On a laptop without discrete GPU, mesa/lavapipe works. - **The desktop's shell is fish** (no `$(...)`, use `(...)`; no `$UID`, use `(id -u)`). Check `$SHELL` here before assuming. ## 4. Substrate invariants (do not undo; tests enforce most of these) **Generated buffers: `Buffer::set_generated_contents` is the ONE authorized write** (terminal copy mode #178) — lift `read_only`, replace via a single whole-buffer `Replace` skipping intercepts, discard history, re-assert `read_only`, and **return the `Edit`**. Three things make it a unit rather than a convenience: - **An intercept is not read-only.** `Buffer::undo` reaches the rope through `ensure_writable` and never consults the intercept chain, so an intercept-only "read-only" buffer is emptied by `M-x buffer.undo`. Rebinding the undo *chords* buffer-locally does **not** close it — `compile.lua`'s own comment says so ("command/menu undo stays dispatchable"). Only rope-level `read_only` does. - **A bare `set_read_only` would be worse than nothing**, because it also refuses the owner's refresh — the operation such buffers exist for. That is why the pairing, not the setter, is the primitive. There is deliberately no Lua `set_read_only`. - **A rope write is only half of an edit.** The returned `Edit` must be fanned out (`notify_buffer_edit_to_windows`, which also queues the daemon-origin CRDT op). Skip it and a displaying window keeps a `TextView` line index describing the previous contents — the next paint indexes the new rope with stale ranges and trips `assertion failed: end <= self.len()` — while replica mirrors never import the write at all. History clearing is load-bearing twice (nothing can pop entries `read_only` makes unreachable, so they leak), and must clear **whichever history the buffer has**: the v0.1 stacks are bypassed in CRDT mode, where it lives in loro's `UndoManager`. That has no `clear`, and needs none — a manager records only what happens after construction, so `CrdtState::clear_undo_history` rebinds a fresh one to the same doc. **Not yet adopted — the inventory is four writer mechanisms covering five buffers.** *Every remaining intercept-protected writer* uses the older idiom: an erroring intercept plus `set_round_trip_input`, written through `bypass_intercept`, with the rope left writable. All are emptiable by `M-x buffer.undo`: | writer | buffers | shape | |---|---|---| | `builtin/runtime/listview.lua:60-61` | every listview panel | delete-all + insert | | `builtin/runtime/compile.lua` (`ensure_slot`) | `*compilation*`, `*shell-command*` | **append** per output batch | | `builtin/commands/default.lua:869` | `*search-results*` | reset per query, then **append** per match batch | | `builtin/runtime/dired.lua:371` | every dired buffer | whole-buffer replace | **Do not read `ensure_slot` as covering the search panel** — it serves `*compilation*` and `*shell-command*` only (`compile.lua:1090,1125`). `*search-results*` is an independent panel with its own intercept, round-trip mark and writes, and `compile.lua` names it only in a predicate. Nor is the scope "every generated buffer": `*workers*`, `*help*` and `*buffer-list*` are generated too but do not use this idiom, and the REPL package's intercept (`builtin/packages/repl/init.lua:187`) is an op-filtering editing policy, not a read-only panel — neither group belongs to this lane. Adoption is not a one-line swap. It inherits the fan-out obligation, and the three appending buffers need a **streaming variant** of the primitive; listview and dired already write whole-buffer replaces and are the cheap half. Recorded in `COHERENCE.md` §14. **And it does not replace `set_round_trip_input`.** The protection is layered across two copies: rope-level `read_only` refuses the op at the daemon; round-trip input stops a semantic frontend applying optimistically to its **own mirror**, which a daemon-side refusal cannot reach — the refusal arrives after the frontend has already painted, so it buys divergence, not prevention. **Command boundaries (Arc 2 kill-ring substrate)** — `EditorCore.command_history: HashMap`, per frontend. Rotate on: keybound command, self-insert, menu invoke, `invoke_interactive` (the M-x path). Break on: unbound key, GPU optimistic CRDT edits, pointer gestures (wheel scroll deliberately does NOT break), unified paste. **Plain `pmacs.command.invoke` stamps nothing** (programmatic API); `invoke_interactive` rotates-then-invokes (Emacs M-x semantics). Single-codepoint optimistic CRDT inserts classify as `buffer.self-insert` (exact decode; `"a("` breaks instead). Lua: `ed.this_command()` / `ed.last_command()`. **Effective-edit returns** — `buf:insert/delete/replace` return the post-intercept `(start, end, inserted_len)`. Callers that care (killring, comment) compare EXACTLY against the request; length-delta and text-at-position checks are documented defeated patterns. Always `pcall` the mutator: a rejecting intercept must report, not throw through, and failed ops must leave no state (kill chains, yank sessions). **Kill ring** — entries `{id, text}` with stable monotonic ids; chains and yank sessions are per-frontend and id-checked (an index is not stable under other frontends' pushes). OS clipboard mirrors to the acting frontend only. Paste is a unified daemon arm keyed by the dispatcher's AUTHENTICATED source — never a payload frontend_id. **LSP outbound positions** — every Position/Range builder in `src/lsp.rs` routes through `outbound_position` (byte → negotiated encoding). Any new request builder must too; UTF-16 servers reject raw byte columns on non-ASCII text. Semantic tokens: `full`, `full.delta`, and `range` are three INDEPENDENT capabilities — gate each. **Persistence (Arc 3)** — state-dir wiring lives in `install_state_dirs()` on real entry points only, NOT `EditorState::new()` (tests stay hermetic); `PMACS_STATE_HOME` overrides. Autosave: one buffer owns a path's recovery slot; only recover/discard release unclaimed crash data; adopt clears the old owner's skip cache. **Protocol** — encoding-breaking bumps are deliberate and versioned. Canonical `main` is `[6..=20]`. The in-review bottom-panel 2B-1 schema extends support to `[6..=21]`, while `ADVERTISED_PROTOCOL_VERSION` stays 20 until 2B-3 provides compatibility-preserving activation; the server-first `Hello` cannot advertise 21 without stranding existing v20 clients before `AttachRequest`. v15 = `CompletionPopup` + `StatusFacts.message`; v16 = `ThemeFacts`; v17 = `FontFacts`; v18 = `StatuslineSegments`; v19 = the vterm terminal family; v20 = semantic `SessionBootstrapRequest` plus appended `InitialTargetResult`; v21 reserves the panel frame/event family. New wire surface ⇒ bump + both-frontends support + acceptance. An APPENDED variant must be guarded by a byte pin on the PREVIOUS final variant — its own round-trip cannot detect a discriminant shift. **Fake LSP** (`src/bin/pmacs_fake_lsp.rs`) modes: `fullonly`, `rangeonly`, `rangeonly16` (UTF-16 + fail-closed bounds validation), `sighelp`. Use these for capability-matrix tests, not real servers. ## 5. Hard-won ops lessons - **A test that skips on a missing precondition reports `ok`, and a gate log cannot tell that apart from a pass.** `vterm_stage3_acceptance::a37` — the only acceptance driving a real daemon, a real PTY and a real wgpu render together — derives `pmacs-gpu` from `CARGO_BIN_EXE_pmacs` and, when that binary is absent from the target directory, prints a skip and returns. A fresh worktree reports the suite 9/9 **in 0.17 s having never run it**; a real run takes ~4 s. `PMACS_REQUIRE_GPU=1` is what promotes the skip to a failure, and the standing gate list applies that flag to `cargo test -p pmacs-gpu`, a *different package*. Two habits follow: build the workspace before believing any suite that reaches for a sibling binary, and **judge such a suite by its elapsed time**, not its verdict. - **Before attributing a red test to your branch, run it on the merge base.** `a37` failed on the #173 branch, which looked like a regression; it failed identically on the PR's own base and on two intermediate commits, and had *passed* on that same base twenty minutes earlier. The variable was machine load from a second agent compiling continuously. Load-sensitive tests make both verdicts uninformative in isolation, so the base-commit run is the cheapest way to tell a regression from weather — and it is much cheaper than the bisect it replaces. - **A daemon-side fix is not deployed until the daemon is restarted from a tree that contains it.** #166's reporter rebuilt and saw no change: the running daemon had been started from a shared checkout still on a pre-fix branch, and `pmacs --gpu` attaches to whatever process already owns the socket. Rebuilding a binary does nothing to a running process. When validating a daemon-side fix by hand, check the running process's binary path and start time against the tree you think you fixed — `ps -eo pid,lstart,args | grep '[p]macs --daemon'` — before concluding the fix failed. - **Two operations that must be alternatives are not made alternatives by being adjacent.** The dispatcher applied its grid and semantic terminal-layout syncs to every attached frontend; a semantic session satisfies both conditions, so its PTY was resized twice per tick forever and the child took a `SIGWINCH` storm that made a GPU terminal untypable while output still flowed. Each arm had a correct `old_size == size` idempotence guard — **individually sound, jointly useless**, because each saw only the size the other had just written. Write mutually exclusive per-frontend-kind work as one `if`/`else` keyed on the same fact session establishment uses, and extract the loop body so a test can drive the real thing. - **Bite against every pre-image the fix could plausibly have taken, not just `main`.** For the same defect, the obvious one-line guard (skip the grid arm for semantic frontends) *does* fix the storm — and silently introduces a controller leak, because that arm was also the only per-tick controller-liveness release a semantic frontend got. A single revert would have scored the fix complete. The pin that catches it (`acc 6`) deliberately **passes on `main`** and fails only against the naive guard: today's defect supplies the release by the accident of running an arm it should not. - **A quiet child is an instrument.** A frame storm is invisible against a fixture that legitimately emits hundreds of frames, and an assertion like `frames >= 2` cannot see one. The same applies to geometry: a "did a frame at the new width arrive" readout is satisfied by a geometry *oscillating through* that width. Assert upper bounds over a fixed window against a child that produces nothing, and let the child self-report the signal you care about (a `SIGWINCH` trap printing a **fresh distinct** breadcrumb per signal — repeated identical markers paint nothing, because `cell::diff` skips already-matching cells). - **`TerminalMode::Raw` makes `sh`-based input fixtures useless.** There is no `ICRNL`, so Enter delivers CR and a `read -r` loop waits forever for a LF that never comes — the test then "proves" input never arrived. Use `exec cat`, which copies stdin to stdout byte by byte. It is also the right echo instrument for the opposite reason people assume: termios `ECHO` is *off* in raw mode, so nothing double-echoes and one keystroke yields exactly one cell. - **Draining the event stream to learn a pid also TICKS, and a tick reaps.** #176's `observing_the_leader_does_not_consume_the_exit_event` failed under load with "process ProcessId(26) is not running": its helper drained for `Started` to read the pid, `drain_until` ticks while it drains, and a tick can observe an immediately-exiting child and move the record out of `Running` — after which `signal` never reaches the code under test at all. It passed standalone only because the drain returned on `Started` before `poll_one` saw the exit. Read the pid **straight from the supervisor record**, which does not tick, and fail fast if the record has left `Running`. **Verified load-bearing under matched load: 0/15 failures with all 16 cores saturated versus 1/10 for the ticking helper.** The general rule: an observation helper that advances the system is not an observation. - **A wait predicate that is WEAKER than the assertion it guards is a race, on every platform that happens to lose it.** #174: the m4 config sink test waited for `contains("probe")` and then asserted `"probe":true` — six bytes further on. The sink is JSONL written by a *separate process*, so the test could read a half-written line; Linux won that race reliably and macOS/lua54 did not, reporting the truncated `{"rust":{"probe":`. **Any "wait until the file mentions X, then assert Y about the file" shape races whenever Y is stricter than X.** The fix is to wait for the exact unit the assertion reads — here a trailing newline, true only once a whole `writeln!` record has landed, and still correct if the payload's field order or spelling changes. Two things generalize beyond the fix: - **A race you cannot reproduce can still be bitten at one remove.** The failure needs a scheduler outcome Linux does not produce, so no local run falsifies it. But `pump_async` *asserts* on its deadline, so replacing the predicate with an unsatisfiable one proves the wait is load-bearing rather than decorative — and restoring the *old* predicate, which still passes locally, proves a green local run cannot distinguish the two. Bite what you can reach and say plainly which claim rests on structure instead of evidence. - **The obvious fix is sometimes worse.** The sibling `m4_26` has the same weak shape and was deliberately left alone: waiting for the expected value would convert a genuine `rootUri` regression — what its `assert_ne!`s exist to catch — into a five-second timeout with a misleading "server didn't initialize?" message, trading a precise assertion diff for a vague hang. Closing it properly needs a record terminator in the fake server first. - **Proving a child has exited is harder than it looks on this codebase.** A fixed sleep is not proof; nix's `waitid` is unavailable on macOS; and `libc::waitid` needs `unsafe`, which `#![forbid(unsafe_code)]` rules out. What works is driving the production diagnostic in a **bounded loop until it observes the exit**. Relatedly, #176's round-1 review replaced every substring assertion with exact message equality built from the kernel-assigned pid — the substring forms would have accepted a hardcoded target or a wrong exit code. - **The checkout may be shared with the user.** Check `git status` for foreign uncommitted work before any stash/checkout/branch surgery; never assume dirty files are yours. (Their uncommitted fix was nearly orphaned once.) A clean status goes stale within minutes when two lanes are active — for parallel work, `git worktree add` a sibling directory off main instead of switching the shared checkout. - **Never `git stash` in this repo.** The stash namespace is REPO-GLOBAL — one list shared across every worktree and with the user; a scripted push/pop can pop a human's years-old stash into your tree (happened during #111: a failed `stash push` chained into `stash pop`, which grabbed the user's PR-#17-era entry). For run-tests-against-an-old-version swaps, use `scripts/bite` — a trap-guarded one-file swap over read-only `git show`, with a two-sided verdict (the tests must PASS now and FAIL against the old version), making bite-verification machine-checkable. - **`scripts/bite` is only as good as its positive control, and it had none until it was given one.** Before that it ran *only* the swapped tree, so it could not tell "my fix is load-bearing" from "my test is broken": a test that fails everywhere made the swapped run fail, and a failing swapped run was the only thing checked, so it printed `bite: OK` and certified nothing. It now asserts the named tests pass **and** that at least one actually ran (a filter matching nothing exits 0, so passing alone is not enough), exiting 3 as `NO CONTROL` otherwise. It also distinguishes `OK (assertion)` from `OK (COMPILE)` — an old file that does not build against the current tree is a much weaker result, because the tests may never have run at all. **Read which one it printed.** - **A fix must be COMMITTED before it is bitten** — but *not* for the reason previously recorded here. This file used to say `scripts/bite` "restores by `git checkout --`, which reverts the file to HEAD", and that a review round's fixes were wiped that way during #165. **That mechanism description is false and was verified false:** the script copies the file to a `mktemp` path before the swap and restores from that copy, under an `EXIT INT TERM` trap, so uncommitted work in the bitten file survives. It has never touched git state beyond a read-only `git show`. The rule still stands on its own merits — gate results must describe the pushed tree, and a `cargo fmt` after a commit splits worktree from branch — but do not repeat the destroys-your-work claim, which will push the next reader toward `git stash` to protect themselves, straight into the repo-global trap above. **The #165 incident itself is now unexplained**, and that is recorded rather than papered over: work really was lost, but not by the mechanism this file blamed. A `SIGKILL` bypasses the trap and would leave the swapped file in place, which is one candidate; so is a stash collision, given the same round. Do not invent a mechanism to close the gap — an unexplained incident is safer than a confident wrong cause, which is what produced this correction. Corollary for a NEW file: the swap-over-`git show` mode does not apply at all, so its claims must be bitten by hand-editing. - **A CONFLICTING PR silently runs no CI at all.** GitHub builds `pull_request` workflow runs against the PR's **merge ref**, which it does not create while the branch conflicts with its base. So pushes land, the branch updates, no run is ever queued, and **nothing reports the absence** — the checks list simply keeps showing the last successful run, which reads as current. Three pushes to #165 produced zero CI before the cause was found, and `gh pr checks` returns nothing usable here. On any lane that lives through a moving `main`, check `gh pr view --json mergeable,mergeStateStatus,headRefOid` and confirm a run exists **for the current head sha**, not merely that a recent run was green. - **Stacked PRs**: retarget the child to main BEFORE merging the parent — GitHub auto-closes a PR whose base branch is deleted and cannot reopen it (#104 → re-opened as #105). - **Frozen reviewed PRs do not absorb moving overlapping work.** For #135 and #137, the approved/frozen #137 landed first; the larger #135 lane then merged canonical `main`, retained its review anchors, and reran every gate. Derive that integration surface from `git diff ..main`, not the other PR's file list — concurrent landed work added an overlap the original two-PR comparison missed. - **Scripted edits (sed/python) in files with repeated similar blocks** (`src/lsp.rs` JSON builders): anchor on a unique line or you will silently edit the wrong block. This produced a vacuously-passing test and cost an hour. - **Acceptance fixtures that open `.rs`/`.py` files** must empty `pmacs.lsp.config` first — the after-load hook spawns real servers (rust/python/c have default configs). Language *detection* (grammars + `pmacs.lsp.filetypes`) is unaffected. - Test scratch buffers have no path ⇒ no language; use tempdir files when language matters. - **Dual-purpose session state is a reset-contract trap** (#120 rounds 2–5): `last_status` doubled as the peer emission baseline AND the stale-diag count freeze, so resetting baselines on `BufferSnapshot` zeroed mid-edit counts. Knowledge about a buffer belongs in shared stores (`DiagnosticStore` severity totals), never in per-session baselines; and any daemon-side reset needs its frontend mirror audited in the same round (the GPU snapshot arm missed search/menu/status the first time). - **Tab width is a rendering semantic, NOT a config gap.** The implementation on `tab-width-parity` fixes the width at the TUI's established 8 columns, shares that constant through `pmacs-protocol`, and expands tabs only in each display projection. Defining `editor.tab-width` could not have fixed the GPU: source text and semantic spans stay byte-addressed while cosmic-text needs projected spaces plus an inverse hit/caret map. A future configurable width would require a buffer-effective frontend fact and cache invalidation; do not re-plan it as a scalar config-only change. - **A test that never runs passes.** Two #127 review-round tests passed vacuously at first: `pmacs.editor.save()` is the RAW save, while `buffer.before-save` fires inside the `buffer.save` COMMAND (`builtin/commands/default.lua`), and `save()` no-ops on an unmodified buffer — so a fixture that opens a file and saves it asserts on bytes nothing rewrote. Dirty the buffer with a real edit and go through `pmacs.command.invoke("buffer.save")`. Caught only because the *other* case failed and the cause was chased instead of the assertion adjusted. - **A message that ALIGNS state cannot be gated on the state it names.** `FrontendEvent::Viewport` both declares a byte range and switches the frontend's window to the buffer it names. Gating the vterm v19 dual declaration on "is the DECLARED buffer a terminal" therefore left a stale in-flight document viewport free to drag a frontend straight back off a terminal a command had just opened — the window oscillated, the terminal declaration was refused every time, and no frame ever arrived. Nothing errored. The gate has to key on the authenticated source's ACTIVE buffer. Generalizes: when two messages declare competing views of "what am I showing", the arbiter is the daemon's own state, never the claim inside either message. - **A pass that sets a mode flag must clear it on EVERY exit.** The semantic producer's terminal pass returned early via `?` when no declaration existed, leaving `terminal_active` set — and the daemon uses that flag to suppress `CursorByte` and the presence sweep, so a frontend that went back to a document silently lost both. Caught by an acceptance assertion, not by any type. - **Sub-crate acceptance needs a real seam, not a fixture.** `pmacs-gpu` depends only on `pmacs-protocol`, so "real daemon + real PTY + real wgpu in one path" could not be an in-crate test. Generalizing `attach::connect`'s reader sink (`connect_with_sink`) and adding `--headless-probe` gave the acceptance the REAL handshake, outbox, writer, and `render_to_view` — which is the whole point; a decoded-message fixture would have proved none of the three fit together. The probe found two real defects the in-process tests did not. - **Real-grid acceptance must budget for macOS startup and path width.** A 100 ms first-Hello timeout failed under loaded macOS CI; use the normal five-second handshake window, then short polling reads. An 80-column split also clipped a custom statusline segment after macOS's long `/var/folders/...` temp path while passing on Linux; size the grid for the longest supported fixture path (the mode-system test uses 160 columns per split). - **A provisional session that fails mid-bootstrap must actually close its socket, not just drop its handle.** #148's dispatcher-side target-failure paths wrote `InitialTargetResult::Failed` and dropped the write-half `UnixStream` clone, but a clone shares the underlying FD — the per-attach reader thread stayed alive with no installed session state. A client that kept the socket open past `Failed` and sent any ordinary event hit an `.expect` reachable only through the new failure path and panicked the whole daemon. Fix: `shutdown(Shutdown::Both)` on every dispatcher-side failure path, plus a defense-in-depth session-registry membership check before any `FrontendEvent` touches render/size/editor state. Generalizes: when a new failure path can leave a handle installed without its owning session, dropping a handle is not the same as tearing down the connection. - **A guard with no production caller passes every direct-call test.** #155 round 1: `EditorCore::try_split_active` implemented the side-window split refusal, but `pmacs.window.split_horizontal` / `split_vertical` — and therefore `C-x 2` / `C-x 3` — still called plain `split_active`. The acceptance test called the core method directly, so reverting the guard entirely would have left every test green. Same shape as folding #142 round 2. Assert through the outermost user-reachable seam (`try_exec(&s, "pmacs.window.split_horizontal()")`), then falsify by revert. When the test shares a file with the code it pins, `scripts/bite` cannot swap it — break the production line by hand and `git checkout --`. - **A geometric readout is not a state predicate.** `TerminalViewStatus::at_bottom` is defined as `scroll_offset == 0` — "the viewport currently reaches the tail", not "this view follows the tail". A still-anchored view satisfies it whenever it happens to be tall enough, so asserting it could not detect that Q#BP7's growth re-arm had never been implemented (#155 round 2): the next rows the child printed pushed the anchored view back into history. Pinning *following* requires advancing the world — feed more child output through a filesystem gate — and asserting the view came along. Related: `scroll_offset` is viewport-relative, so "unchanged across a height change" is vacuous or wrong; the invariant is the frozen ANCHOR. - **A PTY in the default mode does not translate LF to CRLF.** An `echo`-driven test fixture staircases rightward, and past the viewport width every row clips to blanks — so `assert_eq!(top_before, top_after)` compares `"" == ""` and passes for any regression (#155 round 2). Emit `printf '...\r\n'`, and guard text comparisons with `assert!(!observed.is_empty())` the same way the panel daemon pin guards on `!panel_hidden`. - **Widening an ambient resolver into a scoped one can make a total function partial.** #155 round 2 resolved both arms of `pmacs.window.buffer()` through the acting frontend "for uniformity". `acting_frontend` follows the interactive origin, which can name a frontend with no registered view (a bare `dispatch_key` from an unattached peer), so the no-argument arm began raising instead of answering. No runtime caller `pcall`s it, so killring, syntax, autosave, pair, indent and comment silently dropped operations — `kill_ring_acceptance` went 30/30 to 25/5 on every CI platform. The ambient resolver's fallback is what makes it *total*; keep it, and document that as deliberate. Uniformity is not free when the paths have different totality. - **An upgrade decision must be tracked independently of the outcome that triggered it.** #148 published a target's fresh `BufferSnapshot` to existing grid replicas only when the buffer was `newly_loaded || newly_created` — but a target can dedup onto an already-existing, not-yet-CRDT-backed buffer (e.g. one a startup hook created via `find_or_open` and never activated), silently upgrading it without telling pre-attached replicas. The later F29 lazy-upgrade sweep then saw an already-backed buffer and never broadcast it, permanently stranding those replicas on v0.1 round-trip for that buffer. Fix: have the upgrade helper report whether it performed the upgrade, and OR that into the publish decision rather than inferring it from the caller's own load/create branch. ## 6. Named deferrals (the standing backlog, consolidated) Editing: word kills (`M-d`/`M-BS` — need bytes-returning deleters + prepend-on-backward append), `C-SPC` set-mark, `C-u C-y` / `C-M-w`, kill-ring browser + persistence, clipboard watching, block comments + mid-line comment spans, comment-dwim append-at-EOL, per-language comment padding. Pairing (framing "Deferred"): wrap-region on opener, pair-aware backspace, RET-inside-pair closer-on-own-line, in-string/in-comment inhibit (needs node-at-byte `pmacs.parse`), undo amalgamation (pair = one step), balance-aware quotes (the per-buffer toggle SHIPPED in #127 as `editing.auto-pair`). Editops deferrals (full list in its framing): recenter (blocked on viewport facts — the GPU never consumes daemon `view_top`), Unicode case/word classes, region-spanning move/duplicate, locale collation for sort-lines, ensure-final-newline on save. Substrate: buffer-aware edit epoch (after-edit currently compares the ACTIVE buffer only), wire provenance for CRDT self-insert classification, Lua intercept probe, completion.lua still on the old cursor-delta heuristic (migrate to `this_command`), the TUI's nonempty-selection optimistic type-over gate, generated-buffer search invalidation, cross-peer chronological undo arbitration (mixed source/daemon history; pinned by auto-pairing acceptance), origin-pinned `buffer.after-edit` fan-out (a context-switching intercept changes what later callbacks — LSP, completion — observe). LSP/persistence: hidden-buffer LSP attach, daemon desktop-restore, the *warning* half of external-change detection (verify-visited-file- modtime). Config registry (SHIPPED #127; these are its own named deferrals): persistence of settings and the `custom-file` split-brain question, `M-x list-settings` as a listview panel, a settings completion source for the minibuffer (`minibuffer.read`'s `source` is a fixed Rust-side vocabulary), table-valued settings (so `pmacs.lsp.config`, `pmacs.pair.sets`, `pmacs.comment.strings` and the `pmacs.parse.*` write-through proxies stay raw Lua), migrating the remaining scalar setters (`async_config` ×2, `killring.max`, the `enable` booleans) and `pmacs.gpu.set_font`, pending-set staging for names defined after `init.lua` runs, and a `scope = "global"` define flag — `set_local` is currently accepted for `autosave.interval-ms`, where a per-buffer value is meaningless. **Tab width is NOT a config gap** — see §5. Mode system (SHIPPED #129): minor modes, `buffer.after-mode-change`, mode-scoped settings, `describe-mode`, and persistence of explicit major-mode overrides/clears across sessions. Modeline detection (SHIPPED #132): bounded first/last-line Emacs `-*-` and Vim `ft=`/`filetype=` parsing, explicit-over-inferred precedence, alias normalization, and shared fresh-load language pinning for syntax/highlight/LSP startup. Highlight/detection (from the #114–#118 side-quest + injections #122): ~~locals-query processing~~ **SHIPPED #134**; remaining injection follow-ups now that the engine landed (#122) — `injection.combined` (many matches → one shared parse; PHP-in-HTML, some comment schemes), child-tree incrementality + range-scoped layer rebuild (child layers cold-reparse on every settle today), injectable runtime/Lua-registered languages (v1 resolves only against `BUILTIN_LANGUAGES`), and the next injection *consumers* gated on new grammars — HTML/CSS/GraphQL/SQL (`