v0.9.0 Stabilization gate: Windows, large-repo, subagent, and live-state blockers

[Hmbown]

Problem

v0.9.0 should not only add WhaleFlow, Model Lab, and new UI surfaces. It also needs a stabilization gate so old correctness and usability bugs do not ship under a larger feature release.

Scope

Make a release-blocking stabilization lane that triages and closes or explicitly defers the highest-risk runtime issues:

• Windows input and rendering:
  • [BUG] Windows: Input field completely unresponsive to keystrokes (IME composition event deadlock) #1835 Windows IME/input unresponsive
  • TUI-freeze-Windows-crossterm-poll #1812 Windows crossterm poll freeze
  • Bug: Terminal black screen when resizing window after UI appears stuck on Windows Terminal #582 black screen after resize
  • PR fix: Windows sub-agent completion halves TUI render width #2708 Windows sub-agent completion halves TUI render width
• Large repository startup and context loading:
  • 项目非常大,问个你好直接卡住 #1827 huge project “hello” freezes
  • [Performance] Slow initial response (~10s) when launching in directories with many files/subdirectories #697 slow initial response in many-file dirs
• Sub-agent reliability:
  • Subject: Sub-agent 120s API timeout renders agent_open nearly unusable (v0.8.39) #1806 sub-agent 120s API timeout
  • v0.8.60: Sub-agent checkpoint and continue child work across turns #2029 checkpoint and continue child work across turns
  • feat(tools/agent_spawn): teach parent that subagent results are self-reports #719 teach parent that subagent results are self-reports
• Long-running command/live-state correctness:
  • Work Queue Sync Lag & Shell PID Hang Causing Premature LIVE-State Exit During Long-Running Tasks #1786 work queue sync lag and shell PID hang
• Prompt/UI mode clarity:
  • Composer can accidentally enter queued-steer edit state without clear mode feedback #2054 queued-steer edit state lacks clear feedback
  • The dynamic prompts are too flashy. ▃▂▂▃▃▄▅▆▆▆▅▄▃▂▁▂▃▄▅▆▇▇▆▅▄▃▃▃▄▅▆▇▇▇▆▅▄▂▂▂▃▄▄ #1191 dynamic prompts too flashy

Acceptance criteria

• Each listed issue has a disposition: fixed, duplicate, not repro, deferred with reason, or still release-blocking.
• At least one focused regression test or smoke script exists for each fixed blocker class.
• Windows fixes are verified on Windows or documented as unverified with a precise manual test plan.
• Large-repo startup is tested against a synthetic many-file workspace.
• Sub-agent timeout behavior is tested without requiring real provider secrets.
• Release notes call out any remaining known risks.

Non-goals

• Do not fold unrelated v0.9.0 feature work into this lane.
• Do not mask failures by relaxing tests or hiding errors.

[Hmbown]

Status from codex/v0.9.0-stewardship @ 28d6b107697ca85f354922771fcda20f56a67eb0:

Current branch evidence covers several stabilization slices:

• fix: Windows sub-agent completion halves TUI render width #2708 is harvested/closed with terminal-size and fanout-card cache invalidation coverage.
• Subject: Sub-agent 120s API timeout renders agent_open nearly unusable (v0.8.39) #1806/feat(tools/agent_spawn): teach parent that subagent results are self-reports #719 have timeout configuration and sub-agent trust-model/self-report coverage.
• Composer can accidentally enter queued-steer edit state without clear mode feedback #2054's common accidental queued-edit path has labels, Esc recovery, and focused regression coverage.
• v0.8.60: Sub-agent checkpoint and continue child work across turns #2029 supports live timeout checkpoint continuation.
• Work Queue Sync Lag & Shell PID Hang Causing Premature LIVE-State Exit During Long-Running Tasks #1786 has stale persisted-running task recovery.
• [Performance] Slow initial response (~10s) when launching in directories with many files/subdirectories #697/项目非常大,问个你好直接卡住 #1827 have bounded synthetic project-context coverage.

Remaining gate before closing this tracker:

• Real Windows Terminal smoke for [BUG] Windows: Input field completely unresponsive to keystrokes (IME composition event deadlock) #1835, Bug: Terminal black screen when resizing window after UI appears stuck on Windows Terminal #582, and the broader TUI-freeze-Windows-crossterm-poll #1812 input-poll/freeze family.
• Wait for draft integration PR v0.9.0 stewardship integration #2762 CI to finish; as of this comment, macOS tests, Windows tests, and mobile runtime smoke are still in progress while gate, CodeQL, Ubuntu tests, lint, version drift, npm wrapper smoke, and GitGuardian are passing.
• Real massive-repo startup benchmark for [Performance] Slow initial response (~10s) when launching in directories with many files/subdirectories #697/项目非常大,问个你好直接卡住 #1827.
• Decide whether v0.8.60: Sub-agent checkpoint and continue child work across turns #2029 can close on live-timeout recovery or must stay open for cold-restart continuation UX.
• Keep Work Queue Sync Lag & Shell PID Hang Causing Premature LIVE-State Exit During Long-Running Tasks #1786 open for foreground shell hang / LIVE-state watchdog work.
• Treat The dynamic prompts are too flashy. ▃▂▂▃▃▄▅▆▆▆▅▄▃▂▁▂▃▄▅▆▇▇▆▅▄▃▃▃▄▅▆▇▇▇▆▅▄▂▂▂▃▄▄ #1191 as polish/defer unless a current release-blocking prompt/UI regression is identified.

Keeping this tracker open until the manual Windows and large-repo evidence exists.