fix(mobile): keep the one-shot Ctrl armed through terminal-generated reports

Review of #268 turned up two defects, both verified against a real shell
session on an isolated instance.

1. A tap spent the modifier. The onData hook consumed every chunk while
   armed, but not every chunk is a keystroke: a shell session keeps the
   narrow scrollback strip, so mouse DECSETs reach the browser, and with
   vim/htop running a tap arrives as `\x1b[<0;31;23M`. Measured in the
   real app: armed, one tap, disarmed, and the Ctrl button read as dead.
   The hook now skips mouse and focus reports via a new
   `CodemanTerminalInput.isTerminalFocusOrMouseReport()`; they still reach
   the PTY, they just no longer stand in for the next key. Focus reports
   are covered for the same reason even though FOCUS_ESCAPE_FILTER in
   session.ts strips DECSET 1004 today, since the bar refocuses the
   terminal after every key and would spend the modifier on its own
   `\x1b[I` the moment that filter changed.

2. The armed style did not land on the four light skins. The competing
   rule is (0,3,1), not (0,2,1) as the comments claimed: `:is()` takes the
   specificity of its most specific argument and that list holds
   `.btn-toolbar.btn-shell`, so it outranked the (0,3,0) armed rules in
   both stylesheets. Measured across all seven skins at 390px, armed and
   resting backgrounds were byte-identical on paper-gray, solarized-light,
   catppuccin-latte and rose-pine-dawn. The light-skin rule now excludes
   the state as `.accessory-btn:not(.armed)`, which fixes phone and tablet
   at once; adding another class to the armed rules would only have moved
   the tie.

Tests: 20 more cases in test/mobile-shell-keyboard.test.ts (the report
classifier, the gate's effect on the modifier, and a static guard on the
light-skin selector, since the existing E2E background assertion passes on
a light skin and the browser suite runs the dark default), plus a browser
regression that taps the terminal with mouse reporting on.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/web/public/mobile.css

@@ -1163,8 +1163,9 @@ html.mobile-init .file-browser-panel {
   }
 
   /* Armed one-shot Ctrl (shell bar, issue #262). Phone palette is hardcoded in
-     this block, so the state needs its own entry here; three classes to outrank
-     the light-skin .accessory-btn rule at the bottom of this file. */
+     this block, so the state needs its own entry here. Three classes beat the
+     plain .accessory-btn rules; the light-skin rule at the bottom of this file
+     is higher still at (0,3,1) and is excluded by hand there, not outranked. */
   .accessory-btn.accessory-btn-ctrl.armed {
     background: #2563eb;
     border-color: rgba(59, 130, 246, 0.9);
@@ -2918,7 +2919,13 @@ html:is([data-skin="paper-gray"], [data-skin="solarized-light"], [data-skin="cat
   color: var(--text);
 }
 
-html:is([data-skin="paper-gray"], [data-skin="solarized-light"], [data-skin="catppuccin-latte"], [data-skin="rose-pine-dawn"]) :is(.btn-voice-mobile, .btn-settings-mobile, .btn-toolbar.btn-shell, .toolbar .btn-case-add, .accessory-btn) {
+/* `.accessory-btn:not(.armed)` on purpose: this selector is (0,3,1) — `:is()`
+   takes the specificity of its most specific argument, and `.btn-toolbar
+   .btn-shell` is two classes — so it OUTRANKS the (0,3,0) armed-Ctrl rules in
+   both stylesheets and repainted the armed modifier back to a resting button on
+   all four light skins. Excluding the state here fixes phone and tablet at once;
+   adding a class to the armed rules would only have moved the tie. */
+html:is([data-skin="paper-gray"], [data-skin="solarized-light"], [data-skin="catppuccin-latte"], [data-skin="rose-pine-dawn"]) :is(.btn-voice-mobile, .btn-settings-mobile, .btn-toolbar.btn-shell, .toolbar .btn-case-add, .accessory-btn:not(.armed)) {
   background: var(--control-bg);
   border-color: var(--control-border);
   color: var(--text-dim);