The mechanism, without its witnesses yet; tests follow in the next
commits.
**A1-A3 were mapping gaps, and forwarding was half the fix.**
`translate_key` gained F1-F35, Shift+Tab -> `BackTab`, and
`ContextMenu` -> `Menu`. All three already existed in the protocol
`Key` enum and the TUI already sent them, so this closes a divergence
rather than inventing a convention. **`should_forward_key` had to learn
them too** --- translated but unforwarded, they would have mapped
correctly and still done nothing, which reads as a daemon keymap gap
rather than a frontend one. They forward with ANY modifier, like motion
keys: they are command keys that never insert text, so the
chord-withholding rule has nothing to protect them from.
F-keys are an exhaustive match, not arithmetic off `F1`: winit's
`NamedKey` is `#[non_exhaustive]` and its ordering is not a contract, so
an offset would corrupt silently the day a variant is inserted.
**A4 --- every Escape now reaches the daemon and none exits.** The
`intercept || completion_open` test went with the quit branch: it never
decided what to SEND (both arms sent the same `Escape`), only whether to
send at all, and with one behaviour left there is nothing to choose.
Both flags remain live for the OS-paste, round-trip and
completion-accept paths.
**The v24 wire variant is APPENDED and the reason is postcard.** It
encodes a variant by positional index, so widening any variant above
would re-interpret every older peer's bytes. `TextInput` carries an
untrusted `frontend_id` like its neighbours --- the daemon uses the
authenticated source --- plus the text.
**It is not `Paste`, and the difference is behavioural.** A terminal
receives it as RAW UTF-8, never bracketed (A8): a shell that sees
`ESC[200~` treats input as pasted and changes how it handles newlines
and completion. The clipboard slot is untouched, because nothing was
copied. And the document path is ONE edit (A6) --- one undo unit, one
`buffer.after-edit`, one eligible CRDT op --- which is the entire reason
the variant exists, since a two-scalar grapheme sent as two keypresses
is two undo units that a remote edit can interleave.
**A5's precedence is a pure function** (`text_input_payload`) so the
eight rules are testable without a window. A keypress stays `Key` unless
a rule moves it, and only printable MULTI-scalar moves; the version gate
WITHHOLDS rather than degrades, so a `< 24` daemon keeps exactly the
behaviour it has, truncation included.
**A7's ordering falls out of routing through the existing shadow
handlers** one scalar at a time, rather than reaching into prompt state:
history, completion and acceptance stay in one place.
THE 1-PRE EFFECT HARNESS CAUGHT A REAL DEFECT IN THIS COMMIT. Bumping
`PROTOCOL_VERSION` to 24 while leaving `SUPPORTED_PROTOCOL_VERSIONS` at
`..=23` made the handshake reject its own version. All NINE effect rows
failed while the thirteen routing rows passed --- the M21 signature,
meaning `EffectHarness::new` could not attach at all. A pure-routing
harness would have stayed green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
211241a437