fix(terminal): page a hollow Codex transcript with PageUp/PageDown from the first wheel event

config/test-suites.ts

@@ -35,6 +35,7 @@ export const BROWSER_TEST_GLOBS = [
   'test/codex-predictive-echo.test.ts', // also needs a real codex binary
   'test/split-pane-terminal.browser.test.ts',
   'test/terminal-tile-scroll.browser.test.ts',
+  'test/terminal-touch-paging.browser.test.ts',
   'test/shift-enter-keypress.browser.test.ts',
   'test/key-tester.browser.test.ts',
   'test/webhook-settings.browser.test.ts',

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 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`.
+**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()`: the `transcriptPageKeys` capability, 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). ⚠️ The first event of a trackpad-sized gesture (opening under 2 rows) pages AT ONCE and the travel it skipped is owed back by the rest of the gesture (one page per half screen still). Waiting for half a screen first meant an ordinary trackpad flick (well under 19 rows on a 38-row pane) sent nothing at all. A larger opening event is a mouse-wheel notch (100 px is 4 rows) and accumulates as before, or slow notches, each its own gesture past the gap, would page a full screen apiece. ⚠️ What starts a NEW gesture (and so may pre-pay) is narrow, because every boundary is another free page: (1) a TOUCH CONTACT is one gesture, never split by time: the touch paths tag every call, touchmove and momentum frames alike, with `touchId` (one per touchstart), and a different id (or a wheel event after a touch) is a boundary. touchmove only calls once per whole cell of finger travel, so a slow drag arrives as single lines further apart than any gap; on the gap alone 12 lines at 170 ms each sent 12 PageUps (measured through the real listeners, `test/terminal-touch-paging.browser.test.ts`). (2) Outside a contact, 150 ms of quiet (`PAGE_KEY_GESTURE_GAP_MS`), stretched to one second (`PAGE_KEY_DEBT_MS`) while a pre-paid page is still owed in the SAME direction, so slow small wheel ticks (40 px every 250 ms, a Firefox 1-line notch) pay the debt back instead of each pre-paying a page; after a second of quiet the debt lapses and the next small tick pages at once again. The debt also ends the moment travel repays it (reaches or crosses zero): the rest is plain travel and the 150 ms gap applies again. (3) A direction change inside a gesture (within the gap, or within one contact) drops a pre-paid debt (it belongs to the other direction) and accumulates WITHOUT pre-paying, so a +/-3 px trackpad wobble pages once for its opening event and then nothing; a reversal after the gap is a new gesture and pages at once. A tab switch also starts a new gesture. ⚠️ These gesture rules (first-event page, contact and debt lifetimes, reversal handling, notch accumulation, pinch and sideways-swipe consume) are ONE pure helper, `CodemanTerminalInput.pageKeysForGesture(state, ev, lines, rows, now)`, which both panes call with their own state; never re-derive them in a pane. ⚠️ Three gestures are consumed WITHOUT paging: a pinch (`ctrlKey`, Chrome's trackpad-pinch wheel events), a mostly horizontal swipe (both deltas present and `|deltaX| > |deltaY|`; the touch path locks its own axis first), and anything while the pane's OWN session has the alert `'action'` (a pending `permission_prompt` or `elicitation_dialog`, `updateTabAlertFromHooks` in app.js), so a page key never lands in an open dialog's selector; the primary pane logs that case as `page-keys-dialog-open` so a wheel dead under a stale alert leaves a `[scroll]` line. The dialog check is the one rule outside the helper, because it is per pane: the primary pane reads `tabAlerts` for `activeSessionId`, a tile for its own `sessionId` (usually not the active one). ⚠️ Which modes page is the registry's `capabilities.transcriptPageKeys`, published as `window.__codemanTranscriptPageKeys`, never an id check in terminal-ui.js. Today that is claude, codex and opencode. Codex is on it although it is never forwarded the wheel: newer codex draws on tmux's alternate screen, which the full strip hides from xterm, so its pane is hollow too, and PageUp pages its transcript while SGR wheel reports still do nothing. Which version made the switch is not pinned down: alt-screen drawing was observed on 0.157.1 (local) and 0.160 (remote), while 0.147.0 still draws inline; nothing between 0.147.0 and 0.157.1 has been checked. This is the page-key fallback, NOT wheel forwarding, and an older inline codex keeps real local history (`baseY > 0`) so the guard never fires for it. `shell`/`pi` own real terminal scrollback and are never paged, and 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.pageKeysForGesture` on the tile's own state, so the mode rule and the gesture rules stay 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/wiki/The-Dashboard.md

@@ -223,8 +223,12 @@ Worth knowing:
   `~/.claude/settings.json`), so the wheel scrolls the conversation rather than the terminal.
   Claude's default inline view keeps its history in the terminal and scrolls locally. `Shift+Wheel` is
   always local scrollback. OpenCode's wheel and swipes page its own conversation
-  (PageUp/PageDown); in a grid tile or the split view's second pane the wheel does
-  too. Other CLIs scroll locally.
+  (PageUp/PageDown), and so do newer Codex versions, which draw on the alternate screen
+  and leave the terminal no history of its own (an older Codex that draws inline keeps
+  its history in the terminal and scrolls locally). The first small movement of a
+  gesture pages at once, then one page per half screen of travel; one finger on the
+  screen is one gesture however slowly it moves. In a grid tile or the split view's
+  second pane the wheel pages too. Other CLIs scroll locally.
 - **Selection copy.** `Ctrl+C` copies when text is selected and interrupts when it is not.
   `Ctrl+Shift+C` always copies.
 - **Selecting where the CLI owns the mouse.** `Shift+drag` starts a selection even in a pane

src/config/cli-registry/schema.ts

@@ -294,6 +294,10 @@ const capabilitiesSchema = z
     wheelForward: z
       .object({ mode: z.enum(['never', 'version-gated']), minVersion: z.string().max(20).optional() })
       .strict(),
+    // Whether a hollow pane's wheel/touch scroll may be turned into PageUp/PageDown for
+    // the CLI to page its own transcript. Distinct from wheelForward (SGR reports).
+    // Optional: absent means no paging, the safe default for an unmeasured CLI.
+    transcriptPageKeys: z.boolean().optional(),
     keyboardAccessory: z.enum(['agent', 'shell']),
     privilegedCommandGate: z.boolean(),
     startMode: z.enum(['interactive', 'shell']),

src/config/cli-registry/stock.ts

@@ -270,6 +270,10 @@ const CLAUDE: CliEntry = {
     // Declared-for-later: the live rule (`_shouldForwardWheelToApp`, terminal-ui.js) is this version
     // AND the server-published `cliMouseTracking` flag (#498), so wiring this field up needs both.
     wheelForward: { mode: 'version-gated', minVersion: '2.1.187' },
+    // A repaint-mode Claude pane keeps no local history, so when the wheel is not
+    // forwarded (older CLI, inline renderer, the local-scrollback opt-out) a scroll is
+    // turned into PageUp/PageDown, which Claude pages its transcript on (#205).
+    transcriptPageKeys: true,
     keyboardAccessory: 'agent',
     privilegedCommandGate: false,
     startMode: 'interactive',
@@ -496,6 +500,11 @@ const OPENCODE: CliEntry = {
     ...agentDefaults(),
     altScreen: 'strip-mux-and-mouse',
     echo: { policy: 'buffer', anchor: { kind: 'cursor' }, predictProfile: undefined },
+    // Pages its own transcript on PageUp/PageDown (`messages_page_up/down`) and ignores
+    // SGR wheel reports, and its TUI runs on the alternate screen (1.18.31: tmux
+    // `alternate_on=1`, `history_size=0`), so a pane keeps no local history and the
+    // wheel is turned into page keys or it does nothing at all (#555).
+    transcriptPageKeys: true,
     // Measured on a live opencode 1.3.0 pane (capture-pane every 250-300 ms through real
     // turns at 40, 60, 120 and 200 columns, plus the raw PTY stream, 2026-10-09). Every
     // composer row starts with a `┃` bar, and the submitted prompt lands in the transcript
@@ -706,6 +715,11 @@ const CODEX: CliEntry = {
     altScreen: 'strip-full',
     echo: { policy: 'predict', anchor: { kind: 'cursor' }, predictProfile: 'codex' },
     wheelForward: { mode: 'never' }, // #227: codex ignores SGR wheel reports, never forward
+    // ...but it DOES page its transcript on PageUp/PageDown. Measured on 0.157.1 (local,
+    // alternate screen inside tmux, so xterm holds no history) and 0.160 (remote): PageUp
+    // moved the visible transcript while SGR wheel reports and local scrolling did nothing.
+    // This is the page-key fallback for a hollow pane, not wheel forwarding.
+    transcriptPageKeys: true,
     maxFrameBytes: 32 * 1024,
     // codex's own bare-spawn default (no config sent) is already safe (no bypass flag), so
     // the multi-user clamp only needs to force an EXPLICITLY-SENT bypass back off.