feat(session,mobile): auto-resume on usage limit + mobile view fixes

Auto-resume on usage limit ("token pause" control, opt-in checkbox at the
top of the Respawn tab, off by default):
- usage-limit-patterns.ts (new, pure): detects all Claude Code limit
  messages (1.0.x-2.1.x eras incl. "5-hour limit reached - resets 8pm",
  "You've hit your limit - resets 1:40pm (TZ)", weekly date forms, raw
  "usage limit reached|<epoch>") and parses the reset time. Conservative:
  no parseable future reset time, no action.
- SessionAutoOps: arms a timer at reset+2min, sends Esc (dismisses the
  rate-limit dialog) + "continue"; dedups footer redraws, retries every
  5min on stale times, cancels when Claude starts working, persists and
  re-arms across Codeman restarts (SessionState.autoResumeEnabled/At).
- Respawn guard: cycles are blocked while limit-paused so /clear cannot
  wipe the paused conversation (respawnBlocked reason 'usage_limit').
- POST /api/sessions/:id/auto-resume; SSE session:limitPauseScheduled/
  limitResume/limitResumeCancelled; toasts + status line in the modal.
- Respawn tab tidied: single-row prompt fields, merged behavior row.

Mobile fixes (0.9.8 regressions, user-reported):
- Resize arbitration is now activity-based: a desktop sizing claim only
  blocks phone resizes while the desktop typed within 90s
  (Session.DESKTOP_CLAIM_IDLE_MS). Idle desktop -> phone takes the pane;
  next desktop keystroke re-asserts the desktop layout server-side
  (noteDesktopActivity via ws-routes input). Phones re-send dims every
  30s (visible tab only, skipped while the keyboard is open) so attaching
  under a hot claim self-corrects. Fixes the desktop-width-stream-in-
  narrow-xterm soup (mid-word wraps, tmux dot fill, Ink overdraw).
- Cross-device reflows (takeover/re-assert) emit a debounced needsRefresh
  so all clients reload the buffer instead of stacking ghost Ink frames.
- Keyboard accessory/toolbar lift restored: measure keyboardOffset
  against window.innerHeight (layout viewport), not the shrunken .app -
  on iOS the offset computed to 0, leaving both bars hidden behind the
  OS keyboard with a dead gap above.
- Removed the mobile header utility ("three dots") toggle entirely;
  the headerRight tray stays collapsed on small viewports.

Tests: usage-limit-patterns (36), session-auto-resume (21), resize
arbitration (+6), session routes (+4), respawn guard (+2); MockSession
auto-resume/sizing stubs; mobile tabs test updated for toggle removal.

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

src/web/public/mobile.css

@@ -94,30 +94,6 @@ html.mobile-init .file-browser-panel {
     gap: 0.25rem;
   }
 
-  .mobile-header-utility-toggle {
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    width: 44px;
-    height: 44px;
-    padding: 0;
-    margin: -4px 0.2rem -4px 0;
-    background: transparent;
-    border: none;
-    border-radius: 6px;
-    color: var(--text-muted);
-    order: -1;
-    position: relative;
-    z-index: 2;
-    flex-shrink: 0;
-  }
-
-  .mobile-header-utility-toggle.active,
-  .mobile-header-utility-toggle:active {
-    background: rgba(255, 255, 255, 0.08);
-    color: var(--text);
-  }
-
   .header-right {
     position: fixed;
     top: calc(52px + var(--safe-area-top));
@@ -474,25 +450,6 @@ html.mobile-init .file-browser-panel {
     display: none;
   }
 
-  .mobile-header-utility-toggle {
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    width: 44px;
-    height: 44px;
-    padding: 0;
-    margin: -6px 0.15rem -6px 0;
-    background: transparent;
-    border: none;
-    border-radius: 5px;
-    color: var(--text-muted);
-    order: -1;
-    position: relative;
-    z-index: 2;
-    flex-shrink: 0;
-    border-left: none;
-  }
-
   /* Smaller header buttons on mobile */
   .btn-icon-header {
     width: 26px;