## Release v0.51.249 — Release HQ (stage-q21)
Small opt-in feature. UX-approved (screenshot of the toggle in Settings → Preferences).
### Added
| Issue | Author | Feature |
|-------|--------|---------|
| #2974 | @rodboev | **"Auto-expand terminal on output"** preference (Settings → Preferences, **off by default**). When enabled, the collapsed embedded terminal panel expands automatically the first time a running command emits output. Fires once per stream (guarded on open && collapsed — not per chunk), and uses `expandComposerTerminal({focus:false})` so it doesn't steal focus from the composer. Backend-persisted boolean mirroring the `simplified_tool_calling` pattern; default-off = no behavior change on upgrade. |
### Gate
- Full pytest suite: **7557 passed, 0 failed**
- ESLint: CLEAN · ruff: CLEAN · browser-smoke: CLEAN · screenshot vision-verified (toggle renders cleanly under "Compact tool activity", unchecked by default)
- Codex (regression): **SAFE TO SHIP** (clean first pass) — no-arg `expandComposerTerminal` callers unchanged, default-off incl. settings-load-failure path, all 5 plumb sites mirror the existing pattern
Co-authored-by: rodboev <rodboev@users.noreply.github.com>
