Merge pull request #577: fix(tiles): the wheel scrolls Claude's fullscreen transcript in a tile, and Shift+wheel scrolls local history

docs/architecture-invariants.md

@@ -225,7 +225,7 @@ Further detail: the `<prefix>: <title>` form (`w3-myapp: fix the login redirect`
 
 **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 (claude ≥ 2.1.187 while `cliMouseTracking` is true, i.e. fullscreen; 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`.
 
-**A false gate on a hollow pane must not mean a DEAD gesture** (#205 round 2, `_maybePageCliTranscript`): every way `_shouldForwardWheelToApp()` returns false leaves a repaint-mode pane scrolling a buffer that has nothing in it (`baseY === 0`) — the version probe came back empty, the CLI really is older than 2.1.187, the `cliMouseTracking` flag is unset (inline claude, or fullscreen right after a server restart), or the user turned on `terminalWheelLocalScrollback`. **opencode is the fifth case, and the gate is false there by design**: its TUI runs on the ALTERNATE SCREEN (1.18.31 measured: tmux `alternate_on=1`, `history_size=0`), so the buffer is hollow, and it IGNORES SGR wheel reports entirely (six `\x1b[<64;…M` reports against an idle pane left the capture byte-identical) while still paging its transcript on PageUp/PageDown (`messages_page_up/down`) — so paging is the only gesture that can reach it, and without it the wheel was silently dead in every opencode tab. The 1.12.0 retest reported exactly that shape for Claude: a wheel that did nothing at all while Fn+Up (PageUp) paged back through intact text, which is the proof that the CLI's own history and the PTY input path were both fine. So under the guard (`_localScrollbackIsHollow()` — `claude` or `opencode`, gate false, `baseY === 0`) wheel and touch travel is translated into coalesced `\x1b[5~` / `\x1b[6~` through the same 40ms queue as the SGR reports, at half a screen of travel per page key (the key jumps a whole screen; a 1:1 mapping was unusably slow with a discrete wheel). ⚠️ `shell`/`pi` own real terminal scrollback and are never paged, and codex/gemini/antigravity/grok/deepseek/omp page-key behaviour is unverified (`docs/scrollback-fix-plan.md`). ⚠️ Shift is excluded on purpose — it is the explicit "give me local scrollback" gesture and must keep that meaning. ⚠️ `terminalWheelLocalScrollback` is deliberately NOT scoped away from repaint-mode CLIs even though it is a footgun there: that would silently override an explicit user choice, so the fallback catches it instead. **Server-side counterpart**: `getClaudeCliVersion()` caches SUCCESS for the process lifetime but must never cache FAILURE — it used to, so one timed-out or PATH-starved probe at the first Claude session start disabled wheel-forwarding for every Claude session until the server restarted (a dead wheel on phone, tablet and laptop at once, the signature of a server-side cause). Failures now retry with a 1/2/4…15min backoff; the policy is the pure `resolveClaudeCliVersion()`. **Tiles** (a grid tile, the split's Pane B: `TerminalTile`) page the wheel through these same gates, called with the tile's own terminal and session (`_localScrollbackIsHollow(target)`, `_shouldForwardWheelToApp(ev, target)`) and the pure `CodemanTerminalInput.pageKeysForTravel`, so the mode list stays in terminal-ui.js alone. ⚠️ A tile's `baseY` is rarely 0 even when hollow: its first capture is taken at the PTY's previous, taller size and its row-shrinking fits push rows up, so it passes `localRows` with those rows discounted (`TerminalTile._localRows`). ⚠️ So a tile can be hollow with its viewport still up in those rows (Shift+PageUp, a scrollbar drag, a wheel during the first replay), and it pages only while `_terminalViewportAtBottom(tile.terminal)` holds: otherwise every wheel, wheel-down included, was paged and swallowed, the stale rows stayed on screen and the click report (which refuses an off-bottom viewport) went dead too. Off the bottom the wheel stays xterm's, so a wheel-down brings the viewport home. The primary pane needs no such gate: hollow there means `baseY === 0`, which is always at the bottom. Tiles have no touch path and do not forward SGR wheel (tile-grid-plan follow-up 4). Tests: `test/terminal-scroll-routing.test.ts`, `test/terminal-tile-scroll.test.ts`, `test/claude-cli-version-cache.test.ts`.
+**A false gate on a hollow pane must not mean a DEAD gesture** (#205 round 2, `_maybePageCliTranscript`): every way `_shouldForwardWheelToApp()` returns false leaves a repaint-mode pane scrolling a buffer that has nothing in it (`baseY === 0`) — the version probe came back empty, the CLI really is older than 2.1.187, the `cliMouseTracking` flag is unset (inline claude, or fullscreen right after a server restart), or the user turned on `terminalWheelLocalScrollback`. **opencode is the fifth case, and the gate is false there by design**: its TUI runs on the ALTERNATE SCREEN (1.18.31 measured: tmux `alternate_on=1`, `history_size=0`), so the buffer is hollow, and it IGNORES SGR wheel reports entirely (six `\x1b[<64;…M` reports against an idle pane left the capture byte-identical) while still paging its transcript on PageUp/PageDown (`messages_page_up/down`) — so paging is the only gesture that can reach it, and without it the wheel was silently dead in every opencode tab. The 1.12.0 retest reported exactly that shape for Claude: a wheel that did nothing at all while Fn+Up (PageUp) paged back through intact text, which is the proof that the CLI's own history and the PTY input path were both fine. So under the guard (`_localScrollbackIsHollow()` — `claude` or `opencode`, gate false, `baseY === 0`) wheel and touch travel is translated into coalesced `\x1b[5~` / `\x1b[6~` through the same 40ms queue as the SGR reports, at half a screen of travel per page key (the key jumps a whole screen; a 1:1 mapping was unusably slow with a discrete wheel). ⚠️ `shell`/`pi` own real terminal scrollback and are never paged, and codex/gemini/antigravity/grok/deepseek/omp page-key behaviour is unverified (`docs/scrollback-fix-plan.md`). ⚠️ Shift is excluded on purpose — it is the explicit "give me local scrollback" gesture and must keep that meaning. ⚠️ `terminalWheelLocalScrollback` is deliberately NOT scoped away from repaint-mode CLIs even though it is a footgun there: that would silently override an explicit user choice, so the fallback catches it instead. **Server-side counterpart**: `getClaudeCliVersion()` caches SUCCESS for the process lifetime but must never cache FAILURE — it used to, so one timed-out or PATH-starved probe at the first Claude session start disabled wheel-forwarding for every Claude session until the server restarted (a dead wheel on phone, tablet and laptop at once, the signature of a server-side cause). Failures now retry with a 1/2/4…15min backoff; the policy is the pure `resolveClaudeCliVersion()`. **Tiles** (a grid tile, the split's Pane B: `TerminalTile`) page the wheel through these same gates, called with the tile's own terminal and session (`_localScrollbackIsHollow(target)`, `_shouldForwardWheelToApp(ev, target)`) and the pure `CodemanTerminalInput.pageKeysForTravel`, so the mode list stays in terminal-ui.js alone. ⚠️ A tile's `baseY` is rarely 0 even when hollow: its first capture is taken at the PTY's previous, taller size and its row-shrinking fits push rows up, so it passes `localRows` with those rows discounted (`TerminalTile._localRows`). ⚠️ So a tile can be hollow with its viewport still up in those rows (Shift+PageUp, a scrollbar drag, a wheel during the first replay), and it pages only while `_terminalViewportAtBottom(tile.terminal)` holds: otherwise every wheel, wheel-down included, was paged and swallowed, the stale rows stayed on screen and the click report (which refuses an off-bottom viewport) went dead too. Off the bottom the wheel stays xterm's, so a wheel-down brings the viewport home. The primary pane needs no such gate: hollow there means `baseY === 0`, which is always at the bottom. Tiles also FORWARD the wheel to Claude's fullscreen renderer as SGR reports (`TerminalTile._maybeForwardWheelToCli`: the same `_shouldForwardWheelToApp(ev, target)` gate, the cell from `_clientPointToCell(x, y, tile.terminal)`, the bytes from the pure `CodemanTerminalInput.sgrWheelReports` the primary pane's `_sendSyntheticSgrWheel` also uses, flushed through the tile's own coalescer to the tile's session, never the primary queue, which flushes to `activeSessionId`); before that a fullscreen Claude tile left the wheel to xterm, which scrolled only stale replayed frames while Claude's transcript never moved. ⚠️ Shift+wheel in a tile is scrolled by the tile itself (`_maybeScrollLocalOnShift`, `scrollLines()` on the dominant axis), as in the primary pane: xterm's own scroller turns a Shift+vertical wheel into a horizontal one off macOS and Chrome on Windows sends Shift+wheel as `deltaX`, so left to xterm the gesture was dead. Tiles have no touch path. Tests: `test/terminal-scroll-routing.test.ts`, `test/terminal-tile-scroll.test.ts`, `test/claude-cli-version-cache.test.ts`.
 
 **Why the wheel went where it went is LOGGED** (`_logScrollRouting`): one console line per session per distinct decision — `[scroll] <id> → forward-sgr|page-keys|local-scrollback|repull-refused-downgrade (mode=…, cliVersion=…, localScrollbackOptOut=…, mouseTracking=…, localScrollbackRows=…)`. #205 ran two rounds of remote guesswork over questions this line answers directly; keep it when touching the routing.
 

docs/tile-grid-plan.md

@@ -1011,13 +1011,17 @@ exits green. Use the browser runner for those files and read the file count.
    viewer keeps a stale width and renders garbled output (#464).
 3. WebSocket backpressure (`bufferedAmount` threshold, drop and send `{t:'r'}`
    on drain) for grids over slow links.
-4. Tile parity extras: mouse-wheel forwarding for Claude's fullscreen renderer,
-   a "Load full history" action inside a tile. (Done since: a tile pages a
-   hollow buffer's CLI transcript with PageUp/PageDown, the primary pane's
-   #555 route, and hand-reports a plain click while its session has
-   `cliMouseTracking` on, both through the primary pane's gates aimed at the
-   tile. The SGR wheel forwarding itself is still open: a fullscreen Claude
-   tile leaves the wheel to xterm.)
+4. Tile parity extras: a "Load full history" action inside a tile. (Done
+   since: a tile pages a hollow buffer's CLI transcript with PageUp/PageDown,
+   the primary pane's #555 route, hand-reports a plain click while its session
+   has `cliMouseTracking` on, and forwards the wheel to Claude's fullscreen
+   renderer as SGR wheel reports from its own cells
+   (`TerminalTile._maybeForwardWheelToCli`, encoding shared with the primary
+   pane via `CodemanTerminalInput.sgrWheelReports`), all through the primary
+   pane's gates aimed at the tile. Before that, a fullscreen Claude tile left
+   the wheel to xterm, which scrolled only stale replayed frames. Shift+wheel
+   scrolls the tile's local scrollback itself (`_maybeScrollLocalOnShift`),
+   since xterm turns it into a horizontal no-op off macOS.)
 5. WebGL in tiles, after measuring the DOM renderer with nine busy tiles.
 6. Named grid presets, possibly per owner on the server.
 7. The end state: the main terminal becomes a 1x1 grid of `TerminalTile`,