docs(ai): close out PR #150, set PR #153 as active task

- CURRENT_TASK.md rolled forward — the CI-recovery task is complete
  (PR #150 merged as 87bb20b; backend gate is in required checks).
  Active task is now landing PR #153.
- HANDOFF.md rewritten — new resume point is watching CI on the
  rebased SHA 1559feb and merging when all three checks are green.
- SESSION_LOG.md gains a 2026-04-26 entry covering the prefill bug
  diagnosis, fix, regression test, and the rebase off post-#150 main.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.ai/CURRENT_TASK.md

@@ -1,21 +1,28 @@
 # CURRENT_TASK.md
 
+**Task:** Land PR #153 — fix the AssistantChatPage prefill `currentChatRef` bug that silently dropped AI follow-up responses in the task lane.
+
+**Status:** in-progress (CI running on rebased branch)
+
+**Definition of Done:**
+- [ ] PR #153 (`fix/tasklane-prefill-ref`) CI green on the rebased SHA `1559feb`. Backend, frontend, and e2e all pass.
+- [ ] PR #153 merged into `main`.
+- [ ] User-visible verification: from the dashboard, type a prefill, answer a subset of task-lane questions, click *Send N of M Responses* — AI follow-up renders.
+
+**Assumptions:**
+- Rebasing onto post-#150 main pulls in the workflow fixes (no host-port mapping for postgres, no upload-artifact step), so the prior CI failures on this PR are resolved structurally.
+- The new e2e regression spec (`frontend/e2e/assistant-chat-prefill.spec.ts`) doesn't depend on Anthropic — it uses `page.route` to stub `/ai-sessions/*/chat` deterministically, so it should be CI-stable.
+
+**Out of scope (deferred to TODO):**
+- Hardening the `currentChatRef.current !== sentForChatId` silent-return pattern across `handleSend`, `handleTaskSubmit`, `selectChat`, `refreshFacts`, `refreshActiveFix`, `refreshPreview`. PR #153 fixes the specific symptom; the broader audit is its own task in `TODO.md`.
+- Promoting `CI / e2e (pull_request)` to required on `main`. Holding off until two consecutive green PR runs (PR #150 was one; PR #153's run will be the second if it passes).
+
+## Previous task — closed out
+
 **Task:** Land consolidated CI-recovery PR #150 and lock reliable CI gates on `main`.
 
-**Status:** in-progress
+**Status:** complete (2026-04-26).
 
-**Definition of Done:**
-- [ ] PR #150 (`fix/ci-workflow-config`) merged. `CI / backend (pull_request)`, `CI / frontend (pull_request)`, and `CI / e2e (pull_request)` show success before merge.
-- [ ] `CI / backend (pull_request)` added to required status checks on `main` in Gitea branch protection (frontend is already required).
-- [ ] Optional: `CI / e2e (pull_request)` confirmed clean across at least one PR run and added to required checks.
-
-**Assumptions:**
-- The 8-core homelab Gitea Actions runner can support `-n auto` (8 xdist workers). If memory pressure shows up in CI, drop to `-n 4`.
-- pytest-cov's xdist support continues to handle the coverage merge and `--cov-fail-under=50` check correctly.
-- The per-worker DB creation in `conftest.py` is idempotent and racing workers on first import won't all try to CREATE DATABASE simultaneously — postgres serializes that, but if it surfaces issues, wrap with an advisory lock.
-
-**Out of scope:**
-- Frontend lint warnings (23 remain after #149).
-- The 23 react-hooks/exhaustive-deps warnings.
-- RLS test suite (gated behind `RUN_RLS_TESTS=1`; not in default CI).
-- Per-test transactional rollback (would shave another 30-40% off backend time but is a much bigger refactor — capture in TODO if interested).
+- PR #150 merged as commit `87bb20b` on `main`. Backend, frontend, and e2e all green on the merge SHA.
+- `CI / backend (pull_request)` added to required status checks on `main` (alongside the pre-existing `CI / frontend (pull_request)` requirement).
+- `CI / e2e (pull_request)` left as not-required pending one more green PR run.