Add E2E and integration tests (Group 11)

Journal tests (6):
- Home page, auth pages render correctly
- No password fields on register/login
- Protected routes redirect to login

Planner tests (9):
- Session creation via API
- Map loads in session
- Yjs WebSocket connects (Connected status)
- Profile selector, export button, waypoint sidebar
- Session with initial GPX waypoints
- Expired session returns 404

Integration tests (5):
- GPX import returns parsed waypoints
- BRouter computes Berlin routes
- Routes pass through all waypoints (segment by segment)
- Rate limit headers present
- Rejects < 2 waypoints

Total: 32 unit tests + 20 E2E tests, all passing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

playwright.config.ts

@@ -29,6 +29,13 @@ export default defineConfig({
         baseURL: "http://localhost:3001",
       },
     },
+    {
+      name: "integration",
+      testMatch: "integration.test.ts",
+      use: {
+        ...devices["Desktop Chrome"],
+      },
+    },
   ],
   webServer: [
     {