docs(handoff): record Vterm Stage 1 merge

Advance canonical main to the #126 merge, retire the completed active lane, and
record the landed headless terminal core plus the remaining TUI/GPU stages.

docs/active-work.md

@@ -14,7 +14,7 @@ backlog.
   machine-local: `origin` may name this canonical URL, a release mirror,
   or something else, and therefore has no authority by name alone.
 - Canonical base at this snapshot:
-  `githubsucks/main` @ `7bc0c61` (#125 merged; protocol v18).
+  `githubsucks/main` @ `643d1e1` (#126 merged; protocol v18).
 - On the transfer source, `origin/main` named a release mirror at
   `d3fa632` and lagged badly. On the current destination, `origin` names
   the canonical URL. This difference is why all recovery begins by
@@ -48,52 +48,10 @@ git worktree list
 git status --short --branch
 ```
 
-The first command must expose `7bc0c61` or a newer intentional main.
+The first command must expose `643d1e1` or a newer intentional main.
 If it does not, stop and repair the remote/fetch configuration.
 
 
-## Active lane: Vterm Stage 1 terminal core
-
-- Portable branch: `githubsucks/vterm-core`
-- Implementation commits: `bbc1f33` (Stage 1), `962944b` (Darwin signal),
-  first-review fixes `f0a235f`, `28f2e6c`, `bf972a7`, and second-review
-  hardening `9797ada`; current branch head: `fc4e0ce`.
-- Pull request: #126,
-  <https://github.com/levineuwirth/pmacs/pull/126> — open, non-draft, targeting
-  canonical `main`; not merged.
-- State: Arc 5 Stage 2's first of three PRs is implemented, two review rounds
-  are addressed, and the branch is fully gated against protocol-v18 `main`.
-  It is the headless terminal core only; the Stage 2 TUI/Lua surface and Stage
-  3 protocol/GPU renderer are not implemented and must start only after their
-  preceding PR lands.
-- Framing: `docs/vterm-framing.md` Revision 5 maps Stage 1 Acceptance 1–14,
-  records both review rounds, and preserves the downstream TUI/GPU contracts.
-- Final from-start sequence 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. Updated PR CI for `fc4e0ce` is green across Linux/macOS, Lua
-  5.4/LuaJIT, GPU, format, lint, acceptance, and performance jobs.
-- `scripts/bite main src/lib.rs --test vterm_stage1_acceptance` returned
-  `bite: OK` because the old crate root could not compile the new terminal API;
-  this is explicitly weaker compile-time API evidence, not a clean behavioral
-  assertion failure.
-- `scripts/bite HEAD^ src/ansi.rs --lib
-  parser_split_points_produce_identical_screen` returned `bite: OK` with a
-  clean behavioral cursor-position failure against the pre-dispatch parser.
-- `scripts/bite HEAD^ src/terminal/screen.rs --test vterm_stage1_acceptance
-  terminal_cells_reject_child_control_characters` returned `bite: OK` with a
-  clean behavioral control-cell failure against the pre-hardening screen.
-
-Recovery worktree, only if no existing worktree owns the branch:
-
-```sh
-git worktree add --track \
-  -b vterm-core \
-  ../pmacs-vterm-core \
-  githubsucks/vterm-core
-```
-
 ## Parked lane: kill-ring browser + persistence
 
 - Portable branch: `githubsucks/kill-ring-browser`

docs/agent-handoff.md

@@ -1,8 +1,8 @@
 # Agent handoff — cross-machine continuity
 
-**Last updated: 2026-07-21, after Themes Arc 4 completed with
-statusline segments (#125), JSON/YAML (#123), GPU font preferences
-(#124), named UI faces (#120), and multi-language injections (#122).**
+**Last updated: 2026-07-21, after Vterm Stage 1 terminal core (#126)
+landed on `main` atop completed Themes Arc 4 (#120/#124/#125). Vterm
+Stages 2 and 3 are not implemented.**
 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`
@@ -16,7 +16,7 @@ commands, read `docs/active-work.md` immediately after this file.
 
 ## 1. Where the project stands (2026-07-21)
 
-- `main` @ `7bc0c61` (statusline segments #125), protocol **v18**
+- `main` @ `643d1e1` (Vterm Stage 1 #126), protocol **v18**
   (`SUPPORTED=[6..18]`; v16 = `ThemeFacts`, v17 = `FontFacts`, v18 =
   `StatuslineSegments`).
 - **Syntax-highlight / language-detection side-quest (#114–#118)
@@ -155,6 +155,19 @@ commands, read `docs/active-work.md` immediately after this file.
   right-pins the protected suffix under narrow clipping. Review
   hardening pins fixed-face sortedness, retains flattened provider
   tracebacks, and names unavailable layout contexts accurately.
+- **Vterm Stage 1 terminal core LANDED — #126**
+  (`docs/vterm-framing.md` rev 5). `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 a bounded terminal screen, encoders, and the transactional lifecycle
+  registry; one pathless read-only identity buffer anchors each private
+  process/screen. Review hardening added IND/NEL/RI, `TERM=xterm-256color`,
+  portable shutdown liveness, custom-tab-stop preservation, control-free
+  cells, and button-preserving SGR mouse release. Final gates: 1,661 default +
+  1,837 CRDT library tests; 9 default + 10 CRDT Vterm acceptance; 114 M4; 109
+  required GPU; workspace 2,769 across 79 suites; CI green. This is headless:
+  Vterm Stage 2 TUI/Lua and Stage 3 protocol/GPU start as separate PRs from
+  post-#126 `main`.
 - **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
@@ -171,8 +184,8 @@ commands, read `docs/active-work.md` immediately after this file.
     fix (#101).
   - **Arc 4 (themes + extensibility) COMPLETE** — named UI faces (#120),
     live GPU font preferences (#124), statusline providers (#125).
-  - **Arc 5 stage 1 COMPLETE** — compile mode (#113); stage 2 vterm is
-    the next formal roadmap stage.
+  - **Arc 5 terminal stage ACTIVE** — compile mode (#113) and Vterm terminal
+    core (#126) landed; Vterm TUI is the next formal stage.
 
 ## 2. How we work (the part that must not drift)
 

docs/roadmap-2026-07.md

@@ -80,15 +80,20 @@ preference at protocol v17; and composable per-window
 `pmacs.statusline` providers transported to semantic/GPU frontends by
 protocol-v18 `StatuslineSegments`.
 
-### Arc 5 — Terminal, staged ← NEXT FORMAL ARC
+### Arc 5 — Terminal, staged — VTERM CORE LANDED
 
-- **Stage 1 — LANDED (#113)**: compile mode streams line-oriented
-  process output through the PTY/ANSI substrate, with error-regex
-  navigation and `M-x compile`.
-- **Stage 2 (vterm)**: extend `ansi.rs` into a 2D grid model
-  (alt-screen, cursor addressing, scrollback — parser already
-  recognizes and discards these), grid-backed buffer view, GPU
-  rendering question (grid cells vs text buffer).
+- **Compile mode landed in #113**: line-oriented PTY/ANSI output,
+  error-regex navigation, and `M-x compile`.
+- **Vterm Stage 1 terminal core landed in #126**: compatibility parser
+  profiles, bounded VT screen/scrollback/reflow state, input encoders,
+  internal `TerminalManager`, read-only identity buffers, process lifecycle,
+  control-free renderer-boundary cells, and headless real-PTY acceptance.
+- **Vterm Stage 2 TUI is next**: terminal-window composition, input/resize,
+  per-context scroll/selection/copy, and the Lua surface.
+- **Vterm Stage 3 protocol/GPU follows Stage 2**: additive protocol v19
+  complete frames, authenticated daemon routing, and native GPU terminal
+  rendering. Its framing must resolve the 16 MiB transport cap's incompatibility
+  with the legal worst complete terminal frame; never silently chunk.
 
 ### Arc 6 — Folding (keystone gutter rider)