feat(mobile): v1.8 tab switcher + branch indicator + git_status tool

Mobile header is now two rows. Row 1: hamburger | project · branch
indicator (live via GET /api/projects/:id/git, 30s poll) | ModelPicker |
FolderTree. Row 2: pane-switcher pill (hand-rolled BottomSheet) +
NewPaneMenu. Chat-within-pane navigation hidden on mobile; users switch
panes via the sheet. Cross-tab status sync via chat_status frames
published from inference.ts at working/idle/error transitions; StatusDot
component renders amber-pulse/green/red/gray on each pane row and on
desktop ChatTabBar tabs. Level 1 git awareness exposes a read-only
git_status tool to the model, backed by services/git_meta.ts (execFile
+ 2s timeout + 30s cache). Workspace.tsx now receives panes/chats hooks
as props (hoisted into Session.tsx) so the header pill shares state
with the pane grid.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/server/src/routes/projects.ts

@@ -9,6 +9,7 @@ import type { Project, AvailableProject } from '../types/api.js';
 import { resolveProjectRoot, PathScopeError } from '../services/path_guard.js';
 import { listDir, viewFile } from '../services/file_ops.js';
 import { getProjectFiles } from '../services/file_index.js';
+import { getGitMeta } from '../services/git_meta.js';
 import {
   bootstrapProject,
   BootstrapNameError,
@@ -381,6 +382,38 @@ export function registerProjectRoutes(
     }
   );
 
+  // GET /api/projects/:id/git
+  // v1.8 mobile-tabs: feeds the header branch indicator and is the same
+  // resolver the model's git_status tool uses. Returns 200 with branch=null
+  // for non-git directories (not 404) so the UI can degrade gracefully.
+  app.get<{ Params: { id: string } }>(
+    '/api/projects/:id/git',
+    async (req, reply) => {
+      const { id } = req.params;
+      const rows = await sql<Project[]>`
+        SELECT id, name, path, added_at, last_session_id, status, gitea_remote
+        FROM projects WHERE id = ${id}
+      `;
+      if (rows.length === 0) {
+        reply.code(404);
+        return { error: 'not found' };
+      }
+      const project = rows[0]!;
+      let projectRoot: string;
+      try {
+        projectRoot = await resolveProjectRoot(project.path);
+      } catch (err) {
+        if (err instanceof PathScopeError) {
+          reply.code(404);
+          return { error: err.message };
+        }
+        throw err;
+      }
+      const meta = await getGitMeta(projectRoot);
+      return meta ?? { branch: null, is_dirty: false, ahead: 0, behind: 0 };
+    }
+  );
+
   // GET /api/projects/:id/files
   app.get<{ Params: { id: string } }>(
     '/api/projects/:id/files',