refactor: remove legacy Tauri desktop support

Electron updater now uses Electron release metadata only
Removed legacy Tauri package and migration workflow
Replaced Tauri shim usage with the desktop bridge

packages/web/server/lib/package-manager.test.js

@@ -115,27 +115,6 @@ describe('checkForUpdates', () => {
     expect(result.available).toBe(false);
   });
 
-  it('does not cross-check desktop update claims against npm', async () => {
-    fetchMock
-      .when('api.openchamber.dev', {
-        ok: true,
-        json: async () => ({
-          latestVersion: '1.10.0',
-          updateAvailable: true,
-          releaseNotes: '## [1.10.0] - 2026-05-01\n\n- Great new feature',
-        }),
-      });
-
-    const result = await checkForUpdates({
-      appType: 'desktop-tauri',
-      currentVersion: '1.9.10',
-    });
-
-    expect(result.available).toBe(true);
-    expect(result.version).toBe('1.10.0');
-    expect(fetchMock).toHaveBeenCalledTimes(1);
-  });
-
   it('accepts electron desktop update claims without npm cross-checking', async () => {
     fetchMock
       .when('api.openchamber.dev', {