[codex] Fire status listeners at commit point

[proboscis]

Summary

• Moves monitor-plane status listener dispatch from the old O4-only effectFireStatusChange path into Daemon.updateStatus after a successful status append.
• Preserves captured output context on O4-derived status effects so blocked/rate-limited listeners still receive LastOutput.
• Bridges feedback resume (orch send without --no-enter) into the same listener fanout after its legacy append, until O6 is folded into step() v2.
• Updates the C4/I8 design docs and roadmap with the new commit-point law.

Root Cause

Status-change listeners were modeled as a separate step() effect that only stepCaptured emitted for agent inference. Other committed monitor transitions, such as PR closed/merged and dead-session verdicts, used updateStatus but never emitted that listener effect.

before:
  O4 capture -> setStatus + fireStatusChange
  O1/O5     -> setStatus only

after:
  any W1 setStatus -> updateStatus -> AppendEvent ok -> fireStatusChange once
  duplicate/no-op  -> no AppendEvent -> no listener
  append failure   -> error        -> no listener

Verification

• go test -count=1 ./internal/daemon/
  • passed: validates daemon package including new listener tests.
• go test ./internal/daemon/ -run 'TestStatusChangeListenersFireOnceForMonitorTransitionPaths|TestUpdateStatusSameStatusIsNoOp|TestUpdateStatusAppendEventError|TestMarkRunFeedbackSentTransitions'
  • passed: covers agent inference, PR-close terminal transition, dead-session verdict, feedback resume, duplicate no-op, and append failure.
• make lint
  • passed: semgrep architecture rules and fixtures passed.
• go build ./...
  • passed.

Additional Check

• go test ./... was run and failed outside this change:
  • internal/monitor: TestSessionNameForProject expects untruncated project-name prefixes, but current output uses shortened names such as orch-myp-f9a700.
  • test/integration: TestRunWithBuiltInAgents failed when opencode session creation returned HTTP 500 (UnknownError, ref err_0c02feb6).

Issue: inv-fire-status-change-all