fix(pi): leave page keys out, and pin the strip that makes the wheel work

transcriptPageKeys applied to every pi, and a pi in `tuiMode: regular` binds
PageUp/PageDown to its editor. It emits no mouse enable, so the flag stays
false, and on a fresh pane the buffer is hollow: the wheel sent PageUp, the
caret of a multi-line draft moved, and the next keystroke landed on the wrong
line. Measured on real pi 1.1.0, 1.4.0 and 1.5.0. Regular mode is not exotic,
it only takes one line in pi's settings. Telling the two modes apart would
need a new capability, since the paging gate takes no id, so pi has no
fallback: a fullscreen pi with "Wheel scrolls local history" on stays where
master left it.

altScreen, the half of the fix that does the work, was pinned by nothing:
reverting it left 1328 tests green. The strip decision table reads its
expected value from the same registry entry. pi now has its own block using
the bytes it really emits, which also pins that focus reporting survives.

The fullscreen default dates from pi 1.0.0, not 1.4.0, so the comments say
that, and the sites still calling pi narrow-strip or main-screen by default
are corrected. Where a comment listed CLIs it now names the capability.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/web/public/terminal-tile.js

@@ -1149,8 +1149,8 @@
 
     // A plain left-click reported to the CLI, the primary pane's desktop click
     // (terminal-ui.js _handleDesktopTerminalClick) aimed at this pane. The
-    // server strips the mouse DECSETs of some modes (opencode's since #555, so a
-    // drag selects text), which leaves this xterm's own mouse encoder idle for
+    // server strips the mouse DECSETs of some modes (so a drag selects text),
+    // which leaves this xterm's own mouse encoder idle for
     // them; without this a click in such a pane never reached the CLI. Only
     // while this pane's session has tracking on (cliMouseTracking), through the
     // same skips as the primary pane. Bubble phase, as there. The target is

src/web/public/terminal-ui.js

@@ -1572,8 +1572,8 @@ Object.assign(CodemanApp.prototype, {
     // A real mouse click normally reaches the PTY through xterm's own mouse
     // encoder, but that encoder only runs while mouseTrackingMode is ON — and
     // the server strips the enabling DECSETs from claude/codex/gemini output
-    // (isAltScreenStripMode, session.ts) and from opencode's (isMuxMouseStripMode,
-    // so a drag selects text) so the wheel keeps scrolling
+    // (isAltScreenStripMode, session.ts) and from the mouse-strip modes'
+    // (isMuxMouseStripMode, so a drag selects text) so the wheel keeps scrolling
     // scrollback. Desktop clicks therefore stopped reporting entirely (the
     // same breakage the mobile touchend tap branch above works around).
     // Hand-encode the SGR report for plain left-clicks on those sessions.
@@ -5942,8 +5942,8 @@ Object.assign(CodemanApp.prototype, {
    * literal text (`[<0;88;20M`) and they garble the next line typed.
    *
    * Fails toward silence: an unknown or stale flag reports nothing rather than
-   * injecting bytes. After a server restart the flag is false until the CLI
-   * re-emits its DECSET, which closing and reopening a dialog does.
+   * injecting bytes. After a server restart the flag is false until the DECSET
+   * passes again, which tmux does itself when the server re-attaches to the pane.
    *
    * `sessionId` defaults to the primary pane's session; a TerminalTile passes
    * its own (through _handleDesktopTerminalClick's target), never the active one.
@@ -6065,7 +6065,7 @@ Object.assign(CodemanApp.prototype, {
     if (mode && mode !== 'none') return false;
     const session = this.sessions?.get(target.sessionId || this.activeSessionId);
     const sessionMode = session?.mode || 'claude';
-    // GitHub Copilot CLI (and pi, same shape since 1.4.0) scrolls its own transcript on SGR wheel reports (checked with xterm
+    // GitHub Copilot CLI (and pi, fullscreen by default) scrolls its own transcript on SGR wheel reports (checked with xterm
     // encoding them natively). Its mouse DECSETs are stripped server-side so a drag selects
     // locally (strip-mux-and-mouse), which also means xterm no longer encodes the wheel: send the
     // same reports by hand, but only while the CLI is actually tracking the mouse. Not gated on a
@@ -6408,8 +6408,8 @@ Object.assign(CodemanApp.prototype, {
    * The reason is that the habit and xterm's Shift mean different things once
    * the DECSETs are stripped. xterm reads Shift as "force selection" ONLY while
    * the app actually has mouse tracking on; the server strips those DECSETs for
-   * claude/codex/gemini (isAltScreenStripMode) and opencode (isMuxMouseStripMode),
-   * so xterm's mouseTrackingMode is
+   * claude/codex/gemini (isAltScreenStripMode) and the mouse-strip modes
+   * (isMuxMouseStripMode), so xterm's mouseTrackingMode is
    * permanently `none`, that branch is unreachable, and Shift instead falls into
    * `_onIncrementalClick` — EXTEND an existing selection. Extending is a no-op
    * when `selectionStart` is null, so the drag never anchors and no selection is

src/web/routes/session-routes.ts

@@ -332,7 +332,7 @@ const MOUSE_TRACKING_PATTERN = /\x1b\[\?(?:1000|1001|1002|1003|1005|1006|1007)[h
  * - `strip-full` (claude/codex/gemini): alt-screen toggles, `3J` and mouse DECSETs.
  *   xterm obeys the toggles by switching to its scrollback-less alt buffer and wiping
  *   saved lines, so history disappeared on tab switch.
- * - `strip-mux-and-mouse` (opencode, tmux-backed): alt-screen toggles and mouse DECSETs.
+ * - `strip-mux-and-mouse` (tmux-backed): alt-screen toggles and mouse DECSETs.
  *   A replayed tracking enable parks xterm in report mode, where a drag goes to the CLI
  *   instead of selecting text (and Ctrl+C without a selection is opencode's app_exit).
  *   `3J` stays: a TUI is not a `clear` consumer.