Phase 1 low-risk backend batch (on top of Batch A). Both byte-verified vs PR head,
Codex SAFE, 64 own + 749 regression tests pass, coexists with Batch A's #5833.
- #5828 (ai-ag2026): frame CORS OPTIONS preflight with Content-Length: 0 (keep-alive hang fix)
- #5834 (ai-ag2026): parse session _index.json from bytes not decoded str (all 10 sites)
Co-authored-by: t <a@b>
Co-authored-by: ai-ag2026 <ai-ag2026@users.noreply.github.com>
The stale-load guard (#3993 Codex race fix) adds an early at the top
of the loadSession catch block; the test helper anchored on the first
after the catch, which now truncated at the guard. Anchor the body
extraction past the guard (from ) so it captures the 404/non-404
self-heal body as before. Behavior unchanged.
## Release v0.51.248 — Release HP (stage-q20)
Bug-fix.
### Fixed
| Issue | Author | Fix |
|-------|--------|-----|
| #2782 | @rodboev | **A WebUI session whose sidecar was deleted server-side (e.g. `docker compose --force-recreate`) but whose messages remain in `state.db` no longer bricks the chat.** It used to look alive (`GET` 200 from a CLI stub) while every action 404'd (`POST /api/session/draft`, `/api/chat/start`). The GET handler now consults `_index.json`: a deleted **WebUI-origin** session (webui/fork/blank-non-CLI source) returns 404 so the client self-heals (clears saved id, strips the stale `/session/<id>` URL, falls through to the welcome screen). Genuine CLI/imported sessions keep their 200 read-only stub. Client self-heal now also covers mid-session sidecar deletion of the current session. |
### Review fix absorbed (Codex CORE catch)
The first cut collapsed `source_tag or raw_source or session_source or ""`, defaulting a **blank-source** row to WebUI — which would wrongly 404 a **legacy CLI/imported** session that carries `is_cli_session:true` with blank source fields. Now classified **per-field**: any `webui`/`fork` → 404; any explicit non-WebUI source → keep the 200 CLI stub; all-blank → 404 only when NOT `is_cli_session` and NOT `read_only`. + 2 regression tests.
### Gate
- Full pytest suite: **7555 passed, 0 failed**
- ESLint: CLEAN · ruff: CLEAN · browser-smoke: CLEAN · 10 stale-session-restore tests (incl. 2 Codex-catch regressions)
- Codex (regression): CORE legacy-CLI false-404 → per-field fix → **SAFE TO SHIP**
Co-authored-by: rodboev <rodboev@users.noreply.github.com>
