fix(api): always provide credentials to FirebaseApp, improve CI log collection

When FCM_ENDPOINT is set, provide both the custom HTTP client (for
transport redirection) AND credentials (for project ID resolution).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: AchoArnold

.github/workflows/integration-test.yml

@@ -47,8 +47,7 @@ jobs:
         if: failure()
         working-directory: ./tests
         run: |
-          docker compose logs api
-          docker compose logs emulator
+          docker compose logs --tail 200
 
       - name: Stop services 🛑
         if: always()

api/pkg/di/container.go

@@ -414,10 +414,10 @@ func (container *Container) FirebaseApp() (app *firebase.App) {
 				base:   http.DefaultTransport,
 			},
 		}))
-	} else {
-		opts = append(opts, option.WithAuthCredentialsJSON(option.ServiceAccount, container.FirebaseCredentials()))
 	}
 
+	opts = append(opts, option.WithCredentialsJSON(container.FirebaseCredentials()))
+
 	app, err := firebase.NewApp(context.Background(), nil, opts...)
 	if err != nil {
 		msg := "cannot initialize firebase application"