fix(composer): recognize Muse 1.3 input and recover original inbox delivery

[slee029]

Summary

Recognize Muse 1.3's titled composer separator and idle hint rows without treating footer furniture as an unsubmitted draft.
Disambiguate stale idle/done Pi identity only when a single current prompt row and adjacent structured Muse model/effort footer establish the Muse composer shape.
Keep actual input, working/blocked Pi, unknown footer layouts, and shell prompts protected.
Add regression coverage for retrying the original escalated steering-inbox record without re-enqueueing or resetting its delivery budget; acknowledgement remains the delivery proof.

The Muse composer adaptation credits cangele's upstream implementation in the retained commit message.
Rebasing required combining the Muse titled-rule handling with upstream's newly landed footer-zone glyph tracking; both protections are retained.
Verification documentation preserves existing upstream observations and the earlier Muse capture/startup limitations rather than claiming a fresh live pass.

Evidence and limitations

Based on upstream aec043c718ef186a1d28c607fd5852b041e24435.
The combined rebase head tested was 2488fe310400082c3dd088f56c1592313f814131; this PR isolates only the composer/inbox changes, without the terminal reclamation or transport changes.
The isolated PR branch has not received a separate full-suite run.
On the combined head, fm-composer-lib.test.sh passed in 34.9s and fm-composer-ghost.test.sh passed in 7.7s.

The attempted repository run was:

bin/fm-test-run.sh --all --exclude-family real-herdr-gated --per-script-timeout-secs 900

It was interrupted at the 3600-second execution limit, after 50 completed script records, and is NOT a full-suite pass.
Real Herdr tests were excluded because no authorized isolated Herdr lab was supplied.
The composer-matrix live test gate-skipped, so this run does not establish a current installed-harness matrix pass.
Exactly the three failing scripts were then run on pristine upstream, serially with the same 900-second per-script bound:

Script	Combined rebase	Pristine upstream	Assessment
fm-captain-hold-lifecycle.test.sh	exit 124 at 900s	exit 124 at 900s	Same upstream/host failure; cause not diagnosed
fm-ci-workflow.test.sh	exit 1, Ruby absent	exit 1, Ruby absent	Missing host dependency: Ruby
fm-composer-codex-idle-live-e2e.test.sh	exit 1, tmux empty / cursorless styled unknown	same exit and verdict on Codex 0.154.0	Reproduces without local patches; cause not diagnosed

No missing cursor-tool dependency was established; the observed fact is the cursorless classifier result, not a proven explanation.
There is no claim that all remaining tests ran or passed.

Contribution process

Published directly under explicit contributor instruction, without running no-mistakes.
This PR has no no-mistakes attestation and does not claim compliance with CONTRIBUTING's required pipeline; maintainers may require it before review or merge.
No running installation was updated, and no local default branch was moved.