SS5b's first implementation commit: the two appended variants, the
version constants, and the pins that hold them in place. No gating, no
key, no replay --- those are the next commits, and the variants are
REFUSED everywhere until their gate lands.
**APPENDED AT THE TRUE END, confirmed by the discriminants.**
`PanelPointer` is 15, `TextInput` 16, `PanelPointerMapped` **17**;
`Present` 0, `Absent` 1, `PresentMapped` **2**. "Beside `Present`" would
have been adjacent insertion, which shifts every discriminant below and
silently re-interprets an older peer's bytes. `mapping_generation` is a
`u64`, last within each variant, documented invalid at zero --- the
value a default-constructed sender produces, so accepting it would let
a peer opt out of the check by sending nothing.
**THE COMPILER NAMED EVERY SEAM.** Four non-exhaustive matches:
`semantic_render`'s declaration accessor now sees through both
families, and the three routing sites REFUSE the mapped variant rather
than unwrapping it to legacy meaning. Refusal is the correct default at
an intermediate commit, not a placeholder --- until the frontend can
prove it negotiated v25 it IS a `<= v24` peer for gating purposes, and
painting first would ship a window in which the band is hit-tested with
no mapping identity at all.
**Five mutations, each biting its own rows:**
insert `PanelPointerMapped` before `TextInput`
-> the TextInput pin and the mapped pin. `PanelPointer`'s v23 pin
correctly SURVIVES: its discriminant did not move, which is the
"only the pin whose discriminant moved fails" behaviour G0a
specifies
insert `PresentMapped` before `Absent`
-> the Absent pin and the mapped-frame pin
swap `geometry_epoch` / `panel_epoch`
-> the exact-bytes assertion, while the round-trip stays green.
That is the blind spot G0b exists for, and it is why every
adjacent same-typed field carries a distinct value
bump the wire version without extending the supported set
-> both new tripwires and 1a's v6 ladder
move `ADVERTISED_PROTOCOL_VERSION` to 25
-> the baseline pin
**Version fallout, enumerated rather than discovered one gate at a
time.** Four acceptance-suite tripwires (`bottom_panel_stage2b_gpu`,
`discovery_stage2` x2, `vterm_stage3`, `statusline_segments`) each say
"a wire bump must be a conscious edit here" and each worked. Rather
than fix them one run at a time I grepped the tree for version
assertions and updated all four in one pass.
Review folded five further corrections, two of which fix reasoning of
mine that was wrong:
- I claimed reversing `frame` and `mapping_generation` "fails to
compile" because they are different types. **False for NAMED
variant fields** --- the initializer uses names, so reordering the
declarations compiles and shifts postcard's positional bytes
silently. The pin is the only thing catching that.
- Ladder loops now track `PROTOCOL_VERSION` while TRIPWIRES stay
literal. I had flattened both to `25`. A tripwire is literal so a
bump is a conscious edit; a ladder must move, or the next bump
silently stops testing the top rung. G14b is unaffected ---
`PANEL_MAPPING_MIN_VERSION` stays literal, because there the
arithmetic is exactly the hazard.
- `assert!(24 < MIN)` was a compile-time tautology holding for every
value above 24. Replaced with the literal equality plus
`assert_ne!` against `TEXT_INPUT_MIN_VERSION`: the mapped family
must not share v24's gate, or it is admitted on sessions that
negotiated only `TextInput`.
- Statusline support loop reaches `PROTOCOL_VERSION`; public protocol
history records v25.
**CI-red observations are in the LANE LEDGER, not the registry**, and
that is deliberate: `ci-red-signatures.md` here ends at U9 while the
unmerged replay branch already added a U10, so a row from this branch
would duplicate an id or invent one blind --- which this file's own
history records going wrong, two branches' entries merging "without a
conflict, producing duplicate ids across four sites". R7 twice and the
composition budget once, fragments verified, owed to the registry by
whichever branch merges second.
Gates: all eleven green under `env -u TMPDIR` with `--protocol`,
log 20260815T103555Z. Four runs were needed; three were lost to those
two signatures, not to this diff.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
758b985c35