feat(mobile): mobile app navigation rework and beta-feedback closeout (#2561)

Navigation model rebuilt around two full-width drawers and a minimal
header (sessions / title-switcher / usage ring / workspace):

- Left sessions drawer: cross-project tree with live status indicators,
  swipe actions on sessions (rename/archive/delete) and on group headers
  (project edit / two-step close, worktree delete), reorder-only edit
  mode with collapsible project cards and draggable worktrees, app-level
  footer (connected instance, settings, pending web update).
- Right workspace drawer: Changes / Files / Terminal / Notes / MCP as
  pill tabs (inactive tabs icon-only); panes stay mounted once visited.
  The full desktop file editor serves the Files tab; read/skill tool taps
  in chat open the file there at the requested line.
- Header session switcher on title tap: 10 cross-project recents with
  live busy/attention indicators and project · branch metadata; the
  usage ring opens a metadata overlay with an explicit loading state.
- The overflow menu is gone on phones (its destinations moved into the
  drawers); iPad keeps it until its dedicated layout pass.

Correctness and continuity:

- /auth/session answers bearer-first, so a stale WebView cookie can no
  longer mask a revoked device token; cold launches classify failures
  fast and land on an explicit connect screen.
- Authoritative session snapshots raise frozen ordering baselines and
  stale live ranks — recents stay truthful after the app slept.
- Cold launches reopen the last active session per instance (persisted
  pointer, confirmed against a sessions snapshot; a user-opened draft
  clears it), with a logo hold instead of a draft flash.

Also: collapsed pill composer gains the stop control; chat tool rows
share one 36px rhythm; Task subtool rows truncate; larger bottom safe
area so the composer clears big-screen corner radii; Capacitor build
hides About/Update (store updates apply there); widgets link to the
sessions drawer with a list icon; MobileApp split into focused modules;
five mobile-surface detectors unified; translucent borders normalized to
70%; all new strings translated across the 10 locales.

iPad and foldable layouts are intentionally untouched - separate next version PR.

packages/ui/src/index.css

@@ -580,6 +580,19 @@ svg.animate-spin {
   background: transparent;
 }
 
+/* Fully hidden scrollbar for small mobile overlays (session switcher etc.)
+   where a visible bar reads as chrome noise. Scrolling stays intact. */
+.oc-hide-scrollbar {
+  scrollbar-width: none;
+  -ms-overflow-style: none;
+}
+
+.oc-hide-scrollbar::-webkit-scrollbar {
+  display: none;
+  width: 0;
+  height: 0;
+}
+
 [data-scrollbar="chat"].chat-scroll,
 .chat-scroll {
   scrollbar-gutter: stable both-edges;
@@ -952,6 +965,16 @@ html:not(.dark) .chat-scroll {
     height 260ms cubic-bezier(0.22, 1, 0.36, 1);
 }
 
+/* Non-composited variant (left/top-positioned indicator, see
+   nonCompositedIndicator in sortable-tabs-strip): same travel curve. */
+.pill-tabs__indicator--is-animated-layout {
+  transition:
+    left 280ms cubic-bezier(0.22, 1, 0.36, 1),
+    top 260ms cubic-bezier(0.22, 1, 0.36, 1),
+    width 260ms cubic-bezier(0.22, 1, 0.36, 1),
+    height 260ms cubic-bezier(0.22, 1, 0.36, 1);
+}
+
 /* Underline indicator shares the pill's travel curve so both tab styles feel
    like the same control. */
 .underline-tabs__indicator--is-animated {
@@ -972,6 +995,7 @@ html:not(.dark) .chat-scroll {
 
 @media (prefers-reduced-motion: reduce) {
   .pill-tabs__indicator--is-animated,
+  .pill-tabs__indicator--is-animated-layout,
   .underline-tabs__indicator--is-animated {
     transition: none;
   }