phase: 161_reasoning_bubble

All gates verified. Final check — AGENTS.md rules against the project (commands, gates, protocols) — the quick-reference commands all exist and the rules (PLAN §2/§7/§9 references, phase protocol, No CDN, Debugpy, git gates) accurately describe the project; the reasoning bubble is a pure UI change with no new commands or env vars, so no AGENTS.md change is needed.

**Verification complete — full results:**

- **Verified** (implemented by prior task passes, all in working tree): `createReasoningWrap`/`ensureReasoningWrap` live container (D1), `settleReasoning` fold at the 3 settle sites + not at delta (D2), 320px `.reasoning-body` window + pinned-tail follow (D3), zero persistence change (D4), collapsed restore + shared-page parity with D6 step counts, `styles.css` family treatment + reduced-motion still, mock `REASONING_MIDROUND_TRIGGER` flow, 6-test story suite, phase-158 pin updates
- **Full suite:** `uv run pytest` → **3738 passed, 0 failed** · `uv run pytest --cov=app --cov-report=term-missing` → **TOTAL 99% (>90%)** · `uv run ruff check .` → all checks passed · `uv run pyright` → **0 errors, 0 warnings**
- **E2E in isolation** (DB up; port-8123 collision with an unrelated `undercooked` service → `E2E_APP_PORT=8125`/`E2E_MOCK_PORT=8902`, no live change made): `test_reasoning_bubble.py` **6/6** · `test_thinking_timeline.py` ✓ · `test_thinking_display.py` ✓ · `test_tool_call_compact.py` ✓ · `test_big_read_progress.py` ✓ · `test_turn_progress_loader.py` ✓ · `test_share_chat.py` ✓ · `test_chat_persistence.py` ✓ · `test_smoke.py` ✓ (all exit 0, zero failures)
- **Completion criteria:** all 9 checked against the code + test outcomes — container open/live/nested ✓, stays open past mid-round delta ✓, folds at done ✓, restore + shared collapsed with "3 steps" ✓, plain turn = no container ✓, regression suites green ✓, suite/coverage/lint green ✓, diff scope limited to `frontend/assets/{app.js,shared.js,styles.css}` + `tests/` + `README.md` + phase files (no `app/` — D4) ✓
- **Documentation:** README.md "Thinking" section names the Reasoning bubble accurately (320px window, open-until-settle incl. mid-round deltas, "N steps", byte-identical no-container, collapsed on restore/shared) — verified consistent, no changes needed; AGENTS.md — verified consistent, no changes needed; all `.env.example` vars documented
- **Decisions:** commit + phase-dir move left to the harness (per pass rules — no git index/history commands executed); `undercooked` dev server on port 8123 untouched, E2E used the env port overrides
- **Next pending phase:** none — `161_reasoning_bubble` is the last in `todo/`

tests/unit/test_frontend_feedback.py

@@ -145,11 +145,13 @@ def test_thinking_event_is_a_first_class_turn_branch() -> None:
 def test_thinking_run_helpers_are_idempotent() -> None:
     """Phase 158 (D1/D5 — the phase-109 D15 pin, replaced by owner
     direction 2026-10-04): ``ensureThinkingRun`` returns the active
-    run's block or creates a NEW one OPEN above the .bubble (a frame
-    of a new kind closes the previous run first); ``closeCurrentRun``
-    is a no-op without a run and folds the active one (the D15
-    re-open of the shared block is gone — a post-delta thinking frame
-    opens a NEW block)."""
+    run's block or creates a NEW one OPEN (phase 161, D1: appended
+    into the reasoning container's ``.reasoning-body`` — the
+    per-run bubble anchor is superseded; a frame of a new kind
+    closes the previous run first); ``closeCurrentRun`` is a no-op
+    without a run and folds the active one (the D15 re-open of the
+    shared block is gone — a post-delta thinking frame opens a NEW
+    block)."""
     js = _js()
     fn = js.find("function ensureThinkingRun")
     assert fn != -1, "ensureThinkingRun must exist (near addTyping/removeTyping)"
@@ -157,8 +159,13 @@ def test_thinking_run_helpers_are_idempotent() -> None:
     assert "closeCurrentRun()" in body, ("a frame of a new kind closes the "
         "previous run (D1)")
     assert "block.open = true" in body, "D5: created open — the stream is the show"
-    assert "insertBefore" in body
-    assert 'querySelector(".bubble")' in body, "the block sits ABOVE the bubble"
+    assert (
+        'ensureReasoningWrap(wrap).querySelector(".reasoning-body")'
+        ".appendChild(block)" in body
+    ), "phase 161 (D1): appended into the container's body (before the bubble)"
+    assert "insertBefore" not in body, (
+        "the per-run bubble anchor is GONE (phase 161 D1)"
+    )
     fn2 = js.find("function closeCurrentRun")
     assert fn2 != -1, "closeCurrentRun must exist"
     body2 = js[fn2 : js.find("\n}\n", fn2)]