refactor(startup): simplify stack to Tauri-managed OpenFang + optional ChromeDriver

- Remove OpenFang CLI dependency from startup scripts
- OpenFang now bundled with Tauri and managed via gateway_start/gateway_status commands
- Add bootstrap screen in App.tsx to auto-start local gateway before UI loads
- Update Makefile: replace start-no-gateway with start-desktop-only
- Fix gateway config endpoints: use /api/config instead of /api/config/quick
- Add Playwright dependencies for future E2E testing

desktop/test-results/.last-run.json

@@ -0,0 +1,11 @@
+{
+  "status": "failed",
+  "failedTests": [
+    "ea562bc8f2f5f42dadea-a9ad995be4600240d5d9",
+    "ea562bc8f2f5f42dadea-aa98d5dacb19aae6a62f",
+    "ea562bc8f2f5f42dadea-24005574dbd87061e5f7",
+    "ea562bc8f2f5f42dadea-faee21c3e777f7004b5c",
+    "ea562bc8f2f5f42dadea-27f22490c6765498e906",
+    "ea562bc8f2f5f42dadea-233185470e18cdb79c26"
+  ]
+}