<!-- Keep under ~2K tokens. Old handoffs live in SESSION_LOG.md. Do not let this file accumulate history. -->

# HANDOFF.md

**Last updated:** 2026-04-30 (Codex review-fix pass)

**Active task:** **Escalation Mode** wedge — BROWSER QA COMPLETE + review fixes applied. Branch: `feat/escalation-metric-endpoint`. PR #155 ready to mark ready-for-review after committing this fix pass.

## Where this session ended

Code-review fixes were applied after browser QA:

- `claim_session` now uses atomic conditional `UPDATE ... WHERE claimed_by IS NULL` instead of read-then-write, so simultaneous senior pickup cannot silently overwrite `claimed_by`.
- Original escalators cannot claim their own handoff. The escalation queue also excludes the current user's own escalated sessions, preventing the post-escalation dashboard from showing the junior their own handoff.
- `session.escalation_package["handoff_id"]` is now populated from a preassigned UUID instead of `None` before flush.
- Frontend build blockers removed: deleted unused legacy `claiming` / `handleStartHere` path in `AssistantChatPage` and unused `onStartHere` destructuring in `HandoffContextScreen`.

**Validation:**

- `git diff --check` ✅
- `cd backend && pytest --override-ini='addopts=' tests/test_handoff_manager.py tests/test_session_handoffs_api.py tests/test_escalation_bus.py` ✅ `28 passed in 42.23s`
- `cd frontend && /config/.bun/bin/bunx tsc -p tsconfig.app.json --noEmit --pretty false && /config/.bun/bin/bunx tsc -p tsconfig.node.json --noEmit --pretty false` ✅
- Full frontend build could not complete because generated dirs are root-owned in this workspace: `frontend/node_modules/.tmp`, `frontend/node_modules/.vite-temp`, and likely `frontend/dist` produce EACCES. Type errors from review are fixed.

**Not testable in dev (known limitations):**
- "Continue where X left off": requires senior to have existing task lane for session (won't occur on first pickup)
- Browser-level 409 race toast still requires two distinct senior accounts. Backend claim write is now atomic and covered by service/API tests for conflict, self-claim, and idempotent same-user retry.

## Resume point — DO THIS NEXT

**Ship:** Commit this review-fix pass, then mark PR #155 ready-for-review and demo to stakeholder.

Optional before shipping:
- Record Loom demo walking through the escalation flow end-to-end

## Key files changed this session

- `backend/app/services/handoff_manager.py` — `_generate_handoff_summary` replaces old assessment pair; `enrich_escalation_async` unified; `claim_session` eager-loads `handed_off_by_user`
- `backend/app/api/endpoints/ai_sessions.py` — escalation queue excludes the current user's own escalations
- `backend/app/api/endpoints/session_handoffs.py` — self-claim returns 403
- `backend/app/services/flowpilot_engine.py` — `generate_status_update` early-returns saved prose for `context='escalation'`
- `backend/app/schemas/session_handoff.py` — `handed_off_by_name: str | None = None` added
- `backend/app/api/endpoints/session_handoffs.py` — both create + claim endpoints pass `handed_off_by_name`
- `frontend/src/types/branching.ts` — `HandoffResponse` updated with `summary_prose`, `what_we_know`, `confidence: string`, `handed_off_by_name`
- `frontend/src/components/flowpilot/HandoffContextScreen.tsx` — 3-option CTA; `hasTaskLane`, `activeOptionKey`, `onContinue/onAIAnalysis/onOwnThing` props
- `frontend/src/components/assistant/TaskLane.tsx` — `id="task-lane-card-{idx}"` on all card variants
- `frontend/src/pages/AssistantChatPage.tsx` — `handleContinue`, `handleAIAnalysis`, `handleOwnThing` handlers; chip → card navigation; `activeOptionKey` state
- `backend/tests/test_handoff_manager.py`, `backend/tests/test_session_handoffs_api.py` — regression coverage for atomic/idempotent claim, self-claim rejection, queue self-exclusion, and pre-flush handoff ID

## Watch-outs

- Dev stack: backend `:8000`, frontend `:5173`, postgres `:5433` (docker-compose). HMR works.
- Test users (Acme MSP, password `TestPass123!`): `engineer@resolutionflow.example.com` (junior), `teamadmin@resolutionflow.example.com` (senior).
- `handleAIAnalysis` pre-adds `urlSessionId` to `loadedChatIdsRef` before dismissing so the normal selectChat effect doesn't double-fire. It then calls `selectChat` manually before sending the briefing.
- Legacy `claiming` / `handleStartHere` on `AssistantChatPage` was removed; `activeOptionKey !== null` is the active pre-claim processing signal.
- The bus is acceptable for v1 pilot scale only (Railway single-replica). Redis pub/sub is the swap when horizontal scaling appears.