fix(codex): clean up mobile terminal chrome

[foreverrrree]

Summary

• keep Codex's labelled, terminal-width rule rows on one visual line in the wrapped mobile mirror
• suppress Codex's observed rgb(240,240,240) submitted-message fill at phone width, where the light-theme mirror inversion turns it into a solid black bar
• preserve the native ANSI background on desktop and leave semantic diff backgrounds untouched

Why

Codex pads submitted user-message rows to the terminal width and paints the whole row near-white. Collie's light-theme mirror inversion maps that fill to near-black, producing a heavy full-width bar on a phone. Codex also emits labelled separators such as ─ Worked for … ─── that do not satisfy the global pure-rule classifier and therefore wrap into several visual rows.

Both exceptions are presentation-only and scoped to the exact codex adapter. Other harnesses retain the existing global wrapping and colour contracts.

Testing

• cd web && bun run test -- --reporter=dot --maxWorkers=2 --testTimeout=15000 — 118 files, 3,870 passed, 30 todo
• bun run build
• bun test ./bridge ./scripts — 717 passed
• manually verified against a live Codex pane at a 430px mobile viewport: submitted-message black bars are gone and labelled Worked for rules stay on one row

scripts/collie-ctl.test.sh was also attempted, but this Linux host's plutil rejected the generated macOS launchd fixture before reaching any frontend-related assertion.