fix(codex): recognize dim status suffix

[mauhai]

The symptom

Every reply sent from Collie to a current Codex pane was refused with:

The agent's input box isn't on screen — a menu or dialog is probably up. Nothing was typed.

The composer was visibly present and held an ordinary one-line draft (test); no dialog was open.

The cause

Current Codex paints the final collaboration-mode status field together with its separator as one
dim ANSI segment:

<coloured model> · <coloured cwd><dim> · Main [default]</dim>

Collie's context-less status-row detector accepted only alternating coloured fields and standalone
dim separators. It therefore rejected this valid status row, so locateComposer returned null
and the guarded reply path refused to type.

This is separate from #140: that PR fixes deeper indentation in multiline draft continuation rows;
this failure occurs with a one-line draft and is in the status-row parser.

The fix

Accept one combined dim separator + field suffix only when it follows at least two ordinary
coloured fields and is the final segment. The existing paint checks, field bounds, control-character
rejection, and tail-anchored prompt/status shape remain intact. Unstyled lookalikes still fail closed.

Evidence

The parser was run directly against the affected live pane's format:ansi output after the change:

{"composerReady":true,"draft":"test","status":["  gpt-5.6-sol medium · ~/.herdr/worktrees/kausate/feature-kau-6102-repair-dex-services-and-run-tabs · Main [default]"]}

The rebuilt Collie page was reloaded against that pane; the false refusal disappeared and the draft
remained ready to send.

Tests

• pre-push backend typecheck and web typecheck: passed
• backend suite: 691 passed
• collie-ctl.test.sh: passed
• web suite: 3,827 passed / 30 todo
• production build: passed
• scripts/check-version.sh: passed at 0.36.0

Per CLAUDE.md, version files and CHANGELOG.md remain untouched because this is a fork PR.

Suggested changelog line:

- Codex replies work with the dim collaboration-mode status suffix — the composer gate recognises the final ` · Main [default]` renderer segment without accepting unstyled lookalikes

[AltanS]

Thank you — this is a well-diagnosed fix, and the separation from #140 in your description made it easy to review. Verified against main alongside #140, #142 and #121: no conflicts, full suite green (717 bridge tests, 3866 web tests, both typechecks, the ctl lifecycle suite).