fix(omp): drop omp's inline suggestion from the draft the send guard verifies

[enieuwy]

What breaks today

On an omp pane, a reply can stall with "Message didn't reach the input box" while the message really
is sitting in the box. Every retry types it again and stalls again.

omp paints an inline completion suggestion after the operator's text, inside the composer, in its own
foreground colour. It is not in the input buffer, and no Backspace deletes it. It is on the row the
send guard reads back. Live capture (omp v17.2.12), after typing leftover draft here:

\x1b[38;2;190;149;255m╰─ \x1b[0mleftover draft here\x1b[0m\x1b[38;2;111;115;119m's\x1b[0m … ─╯
                                                        ^^ omp's ghost, in its muted colour

The chain:

1. harness/omp/chrome.ts → extractInputDraft returns leftover draft here's.
2. reply-action.ts → draftCarriesSend requires the visible draft to be contained in what was
   typed. 's is not, so the claim fails.
3. The guard withholds the submit key and reports the stall. The bridge did nothing wrong. The
   adapter answered a screen question wrongly.

This fires on ordinary prose, on anything omp offers a completion for. On this host it hit most
sends.

The fix

composerGhost (harness/omp/markers.ts) claims the trailing run of coloured segments that follows
unstyled text on the composer's bottom border, the row the caret is on. extractInputDraft subtracts
that run before it returns the draft.

The rule is relative, like the rest of this adapter:

• No colour literal and no threshold. The operator's own text is what the terminal echoed, so it is
  unstyled. omp's suggestion is the styled tail after it. Themes and truecolor palettes stay free to
  change.
• It claims nothing on a row that has no unstyled text of its own. A fully-coloured row is ambiguous,
  because it could be a themed draft.
• It claims nothing on a row that is not a composer bottom border. A wrongly-claimed ghost would
  shorten the draft the guard checks, which is the unsafe direction.

This also fixes the stranded-draft chip and "Take over". Both used to copy the suggestion into the
phone composer as if the operator had typed it.

Evidence

• Reproduced on a live sandbox omp pane (2026-08-23) driving pane.send_text and pane.read
  directly. Before the patch, draftCarriesSend → false on two separate ghost captures. After it,
  true.
• New fixture omp--draft-ghost-suggestion.txt, derived from omp--draft-single.txt. The SGR run and
  six ghost cells were spliced in and six padding cells taken out. The row still measures 189 display
  cells and keeps its 28 rows, its LF endings and every other byte. It is registered in the corpus
  lists and the fixture README, and the census sentences that count captures were updated with it.
• New tests: five composerGhost cases in omp/markers.test.ts, the fixture's draft in
  omp/chrome.test.ts, and an end-to-end sendGuardedReply case in reply-action.test.ts on an omp
  pane whose composer shows a suggestion. Both new behavioural assertions fail without the patch. I
  checked that by reverting the strip.
• End-to-end on the deployed build: the phrase that used to stall now shows "Sent ✓" in the web UI,
  and omp starts working on it.
• web: harness and reply suites pass, tsc clean. Root bun run test: 688 pass.

Notes for the maintainer

No version bump and no CHANGELOG entry, per CLAUDE.md's fork rule. A line for the release, if you
want one:

• Every reply to an omp pane could stall with "Message didn't reach the input box" — omp paints an
  inline completion suggestion after your text, and the send guard read it back as part of the draft

[AltanS]

Merged — thank you, this is a model diagnosis. The relative no-colour-literal rule and both fail-closed refusals are exactly right, and the containment failure chain in the description made review trivial. I rebased onto today's codex/grok adapter merges on our side (one comment-paragraph conflict) — your fixture now also runs foreign against those two corpora automatically. Gates after the rebase: root 687, web 3429, typechecks clean.