feat(terminal): refactor runtime and add mobile workspace (#2280)

Replace the legacy terminal flow with a shared authenticated WebSocket
runtime used across web, desktop, relay, and mobile surfaces.

- introduce the v3 terminal protocol with scoped attachments, snapshots,
  ordered output, bounded replay history, reconnects, and explicit lifecycle
- harden PTY creation, restart, resize, close, force-kill, idle cleanup,
  shell selection, login mode, environment sanitization, and appearance sync
- add runtime-aware terminal APIs with relay authentication and Electron parity
- add a fullscreen mobile terminal workspace with touch scrolling,
  long-press selection, safe-area controls, quick keys, and Ctrl/Alt input
- add terminal selection attachments, preview detection, project actions,
  shell settings, and localized UI
- harden Ghostty rendering, resize recovery, Unicode handling, block
  characters, line height, and stale-row behavior
- remove the obsolete terminal SSE path and update reverse-proxy guidance
- expand terminal runtime, transport, input, selection, and store coverage
- avoid duplicate web builds when preparing mobile assets in root CI builds

packages/web/server/lib/opencode/settings-helpers.test.js

@@ -78,6 +78,19 @@ describe('settings helpers', () => {
     expect(helpers.sanitizeSettingsUpdate({ messageStreamTransport: 'websocket' })).toEqual({});
   });
 
+  it('sanitizes the persisted terminal shell', () => {
+    const helpers = createTestHelpers();
+
+    expect(helpers.sanitizeSettingsUpdate({ terminalShell: ' ZSH ' })).toEqual({ terminalShell: 'zsh' });
+    expect(helpers.sanitizeSettingsUpdate({ terminalShell: 'auto' })).toEqual({ terminalShell: 'auto' });
+    expect(helpers.sanitizeSettingsUpdate({ terminalShell: '/bin/zsh' })).toEqual({});
+    expect(helpers.sanitizeSettingsUpdate({ terminalShell: 'zsh -c whoami' })).toEqual({});
+    expect(helpers.sanitizeSettingsUpdate({ terminalLoginShells: [' ZSH ', 'bash', 'zsh', '/bin/fish', 42] })).toEqual({
+      terminalLoginShells: ['zsh', 'bash'],
+    });
+    expect(helpers.sanitizeSettingsUpdate({ terminalLoginShells: [] })).toEqual({ terminalLoginShells: [] });
+  });
+
   it('accepts desktopLanAccessEnabled as a persisted shared setting', () => {
     const helpers = createTestHelpers();