chore(agent): phase roadmap from TODO.md — 8 phases (40–47), 24 tasks

Converts the 9 TODO items into an executable phase roadmap (Protocol B,
appended after phase 39):

- 40 tuning toggle anonymous flash (TODO L3)
- 41 sync fail-fast + modal when a model is down (TODO L4)
- 42 no reply autoscroll (TODO L5)
- 43 thinking scroll back — user scroll + gated autoscroll (TODO L7)
- 44 markdown tables (TODO L6)
- 45 agent unlimited tool calls behind BOR_AGENT_MAX_ROUNDS (TODO L8)
- 46 mobile hamburger nav (TODO L9)
- 47 quadlet + jinja import formats, A9 revision (TODO L10–L11)

Each phase carries a user story, a dedicated Playwright E2E suite plan,
and owner-locked decisions (R1 A9 format extension, R2 phase-37 budget
revision, A1–A5 scope decisions) confirmed 2026-08-27.

Also records the completed phases 30–39 todo/ -> complete/ moves that
were pending in the working tree. TODO.md is cleared (items now live in
.agent/phases/todo/).

.agent/user_stories/no-reply-autoscroll.md

@@ -0,0 +1,91 @@
+# Story: No reply autoscroll
+
+**Phase:** `42_no_reply_autoscroll` · **Source:** `TODO.md` L5 ·
+**E2E:** `tests/e2e/test_no_reply_autoscroll.py`
+
+## Bug report (verbatim, `TODO.md` L5)
+
+> "Get rid of the chat reply autoscroll, it's breaking things like
+> making it impossible for the user to scroll while a reply generates."
+
+## Narrative
+
+As **a user reading a long answer**, I want full control of the
+viewport while Brain replies. Today the page auto-scrolls to follow the
+stream (phase 18 "follow-the-bottom"): while I'm in the 200px
+near-bottom band the page is yanked down on every thinking / tool /
+delta frame, which fights my own scrolling mid-answer. The reply
+autoscroll is being **removed** — the page only scrolls when I
+explicitly cause it.
+
+- **Given** a reply is streaming (thinking, tool calls, or answer text)
+- **When** I scroll up to read earlier context
+- **Then** the viewport stays exactly where I put it for the rest of the
+  turn — no frame yanks it back.
+
+## Acceptance criteria
+1. **No streaming autoscroll:** during a long thinking stream, a tool
+   call, and a long answer, the page never auto-scrolls — sampled
+   `window.scrollY` is stable (within 1px) across frames while the
+   viewport is away from the bottom.
+2. **Submit reveals my message:** sending a question while scrolled up
+   still scrolls the viewport down so my own message is visible
+   (user-initiated — kept by owner decision).
+3. **Restore landing kept:** reloading a persisted conversation
+   (phase 14) still lands one-shot on the latest message.
+4. **The phase-18 gate is gone:** `NEAR_BOTTOM_PX` /
+   `isNearBottom()` and the per-frame `scrollReveal` calls in the
+   thinking / tool / delta handlers are removed from `app.js`; the unit
+   pin (`tests/unit/test_frontend_scroll.py`) is rewritten for the new
+   contract (scrolls happen only on submit + restore landing).
+5. **Everything else unchanged:** the thinking window's *internal*
+   bottom-pin (phase 17 — `textEl.scrollTop`, not the page) is untouched
+   in this phase (phase 43 reworks it separately); message rendering,
+   persistence, UI states, and the 120 s guard are unchanged.
+
+## Owner-confirmed (2026-08-27, roadmap A1)
+1. **"Reply autoscroll" = the phase-18 follow-the-bottom auto-follow on
+   thinking / tool / delta frames.** Removed.
+2. **Kept:** scroll-on-submit (reveal the user's own message) and the
+   one-shot restore landing on page load.
+
+## UI Visualization & Structure
+- **The functional change is in `frontend/assets/app.js` only:**
+  - delete `export const NEAR_BOTTOM_PX = 200`, `isNearBottom()`, and
+    the `force`-optional gating in `scrollReveal` — the helper becomes an
+    unconditional `scrollIntoView` (still smooth, still still under
+    `prefers-reduced-motion` via the existing `SCROLL` constant);
+  - `addMessage(...)` gains an explicit "scroll" intent: the **user
+    submit** path scrolls (shows my message), brain bubble creation and
+    the typing indicator do **not**;
+  - the thinking / tool / delta handlers drop their `scrollReveal(wrap)`
+    calls (the thinking handler keeps its `textEl.scrollTop` window-pin —
+    phase 17, reworked in phase 43);
+  - the phase-14 restore landing keeps its one-shot forced scroll;
+  - module docstrings updated (the phase-18 contract block is replaced
+    by the new "no reply autoscroll (owner direction 2026-08-27)"
+    contract).
+- **Non-goals:** no new UI element, no "↓ new content" pill (the owner
+  wants silence, not a substitute affordance), no change to the
+  composer / safe-area layout.
+
+## Playwright Mapping Rule
+**Test Scenario → `tests/e2e/test_no_reply_autoscroll.py`** (mock LLM;
+DB up; the phase-18 suite `tests/e2e/test_follow_bottom_scroll.py` is
+**deleted** in this phase — its behavior is intentionally removed):
+1. `test_no_autoscroll_during_long_answer` — `LONG_ANSWER_TRIGGER`
+   question; once the answer starts, scroll the viewport up ~2× the
+   answer height; sample `window.scrollY` across ≥10 streaming frames:
+   stable within 1px; after `done` the viewport is still where it was.
+2. `test_no_autoscroll_during_thinking` — `THINKING_TRIGGER` question;
+   scroll up during the ~4.5 s thinking stream; the viewport stays
+   pinned (no per-chunk page follow).
+3. `test_submit_reveals_user_message` — scroll to the very top of a
+   populated conversation, send a question; the viewport ends with the
+   user's message visible (bottom in view).
+4. `test_restore_landing_one_shot` (phase 14 regression) — settle a
+   conversation, reload; the page lands on the latest message one-shot
+   and stays there while no stream is active.
+5. `test_answer_content_intact` (regression) — the long answer streams
+   to completion with sources and (for thinking) the collapsed block,
+   persisted and restorable.