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/src/store/connectionStore.ts

@@ -219,6 +219,26 @@ export const useConnectionStore = create<ConnectionStore>((set, get) => {
           } catch {
             /* ignore local gateway preparation failures during connection bootstrap */
           }
+
+          // Auto-start local gateway if not running
+          try {
+            const localStatus = await fetchLocalGatewayStatus();
+            const isRunning = localStatus.portStatus === 'busy' || localStatus.listenerPids.length > 0;
+
+            if (!isRunning && localStatus.cliAvailable) {
+              console.log('[ConnectionStore] Local gateway not running, auto-starting...');
+              set({ localGatewayBusy: true });
+              await startLocalGatewayCommand();
+              set({ localGatewayBusy: false });
+
+              // Wait for gateway to be ready
+              await new Promise(resolve => setTimeout(resolve, 1500));
+              console.log('[ConnectionStore] Local gateway started');
+            }
+          } catch (startError) {
+            console.warn('[ConnectionStore] Failed to auto-start local gateway:', startError);
+            set({ localGatewayBusy: false });
+          }
         }
 
         // Resolve effective token: param > quickConfig > localStorage > local auth