fix(terminal): take the wheel in capture phase; xterm's scroller is deaf after reset

Measured on the live instance: xterm's vscode-style viewport scroller
consumes wheel events itself whenever it believes a scrollbar exists
(preventDefault + stopPropagation, attachCustomWheelEventHandler is not
consulted), so Codeman's bubble-phase handler never fired once local
scrollback existed. Forwarding, the deltaMode conversion and the
top-of-buffer history re-pull were all silently dead exactly on the
sessions that had history, which is the 'input box scrolls up then it
fights and hangs' report. Worse, that scroller's dimensions go stale
after terminal.reset(): following a tab switch or full-history replay it
neither scrolls nor propagates, which is the 'works at first, breaks
after reload and tab switch' report.

The container wheel listener now runs in capture phase, stops
propagation, and scrolls locally through buffer-level scrollLines(),
which keeps working after resets. Mouse-tracking sessions and the
alternate buffer (direct-PTY vim/less) are passed through untouched so
xterm's encoder and alt-scroll arrow conversion keep owning those.

Verified end to end against the beta: 9/9 matrix checks including the
exact reported flows (claude wheel with scrollback present stays pinned
and forwards, shell reaches full history by wheel alone, reload then tab
switch then back still works, SSE reconnect survives, Shift+wheel stays
local), plus the two prior E2E suites re-passing 10/10 and 6/6.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/architecture-invariants.md

@@ -66,6 +66,8 @@ Implementation detail extracted from `CLAUDE.md` so that file stays small enough
 
 **Wheel/touch forwarding is NOT gated on viewport-at-bottom** (#205, `terminal-ui.js:_shouldForwardWheelToApp`): for sessions verified to scroll their own transcript on SGR wheel reports (codex, claude ≥ 2.1.187 — version via the local/docker/remote `--version` probes), the plain wheel AND touch drags forward as coalesced SGR reports (`_forwardScrollToApp` → `_sendSyntheticSgrWheel`, 40ms batches, 5-tick cap, 512-byte queue bound). It used to gate on the viewport being at the bottom so both scrollbacks stayed reachable, but a repaint-mode CLI keeps NO terminal scrollback of its own — xterm's buffer holds only replayed repaint frames, so local scrolling drags the CLI's pinned prompt box up the screen over stale frames; and `scrollToLastNonEmptyLine()` routinely parked the viewport off-bottom, silently pinning the wheel to local. Forwarding now snaps the viewport home first (SGR coordinates address the LIVE screen — a report computed from a scrolled-up viewport would hit-test the wrong row). Local scrollback remains on Shift+wheel and the `terminalWheelLocalScrollback` opt-out (both also cover touch via the shared gate; touch has no Shift, so the setting is its only local pin). `_wheelScrollLines()` normalizes `deltaMode` (Firefox fires LINE deltas ≈3/notch — read as pixels that rounded to 0 and fell to the ±1 fallback, ~4× too slow; PAGE deltas scale by `terminal.rows`) while keeping the #154 Shift-axis trap (macOS trackpads put Shift+scroll magnitude on deltaX). Tests: `test/terminal-touch-tap.test.ts`.
 
+**The wheel listener is CAPTURE-phase and Codeman owns the scroll** (#205 follow-up, measured on the live instance): xterm's viewport is a vscode-style ScrollableElement that consumes wheel events itself (preventDefault + stopPropagation) whenever it believes a scrollbar exists, ignores `attachCustomWheelEventHandler`, and goes DEAF after `terminal.reset()` — a tab switch or full-history replay leaves its scroll dimensions stale, after which wheel events neither scroll nor propagate reliably. A bubble-phase container listener therefore never fired once local scrollback existed (forwarding, deltaMode and the top-of-buffer re-pull all silently dead exactly on sessions WITH history), and after a tab switch nothing scrolled at all ("works at first, breaks after a tab switch"). The container wheel listener is `{capture: true}`, stops propagation, and scrolls locally via buffer-level `terminal.scrollLines()` (immune to the stale scroller). ⚠️ Two cases are deliberately passed through untouched, in this order BEFORE preventDefault: `mouseTrackingMode !== 'none'` (xterm's encoder forwards the wheel to the PTY — htop/vim with mouse on) and `buffer.active.type === 'alternate'` (direct-PTY vim/less: xterm's alt-scroll converts the wheel to cursor keys). Do not "simplify" this back to a bubble listener or re-delegate local scrolling to xterm's viewport. E2E guard: the reload → tab-switch → wheel matrix in the #205 verification scripts.
+
 ### Run launch synchronization
 
 **Run launch synchronization**: the main Run entrypoint in `session-ui.js` holds an in-flight lock and disables `#runBtn` for the whole launch (at least 500ms), so a double click cannot create duplicate sessions with the same `w<n>-<case>` name. A successful create/quick-start also calls `_ensureCreatedSessionVisible()` before `selectSession()`: local creates use the response's full session snapshot; quick-start modes fetch `GET /api/sessions/:id` only when `session:created` SSE has not already populated the map. The normal `_onSessionCreated()` handler remains the idempotent upsert, so POST-first and SSE-first ordering both produce one immediately-rendered tab. Tests: `test/run-mode-ui.test.ts`.