feat(crashlytics): add optional email alerting step to web onboarding

[tonybaroneee]

Description

Adds an optional interactive step to firebase crashlytics:onboard:web (gated behind the crashlyticsWebAlerts experiment) that allows users to configure Crashlytics email alerts for their Web app during onboarding:

• Alert Policy & Notification Channel Helpers (src/crashlytics/alerts.ts, src/gcp/cloudmonitoring.ts):
  • Calls the Crashlytics projects.apps.generateAlertPolicy API to provision Cloud Monitoring alert policies for selected alert types (ALERT_TYPE_NEW_ISSUE, ALERT_TYPE_REGRESSED_ISSUE).
  • Queries or creates a Firebase-labeled Cloud Monitoring email notification channel (is_firebase_channel=true) for the authenticated user's email and attaches it to the generated alert policies.
• Interactive Onboarding Step (src/crashlytics/onboarding.ts):
  • When the crashlyticsWebAlerts experiment is enabled and the CLI is running interactively, prompts the user to select which email alerts to enable (New issues and/or Regressed issues, both checked by default).
  • Gracefully logs a warning without failing the overall onboarding flow if alert configuration encounters an error or if the user's email cannot be determined.

Example Output

$ firebase crashlytics:onboard:web 1:1234567890:web:abcdef1234567890 --project my-project

i  crashlytics: Enabling required telemetry APIs...
✔  crashlytics: Telemetry APIs enabled.
i  crashlytics: Ensuring Crashlytics Telemetry API is permitted in API key restrictions...
✔  crashlytics: API key restrictions updated for Crashlytics Telemetry.
i  crashlytics: Setting up Cloud Logging bucket 'firebase-telemetry'...
✔  crashlytics: Cloud Logging bucket configured.
i  crashlytics: Setting up Cloud Logging routing sink 'firebase-telemetry-routing'...
✔  crashlytics: Cloud Logging routing sink configured.
i  crashlytics: Configuring Crashlytics telemetry for web app...
✔  crashlytics: Crashlytics telemetry configured successfully.
? Which email alerts would you like to enable? (Optional)
 ◉ New issues (Notify when a new issue is detected)
 ◉ Regressed issues (Notify when a closed issue reoccurs)
i  crashlytics: Setting up Crashlytics email alerts for user@example.com...
✔  crashlytics: Crashlytics email alerts configured successfully.

Scenarios Tested

• Unit tests:
  • src/crashlytics/alerts.spec.ts: Generating alert policies, reusing existing vs. creating new Firebase email notification channels, deduplicating channels on policies, and enabling multiple alert types in parallel.
  • src/crashlytics/onboarding.spec.ts: Interactive alert selection, deselecting all alerts, skipping when crashlyticsWebAlerts is disabled or in --non-interactive mode, resolving email from options.user.email vs. requireAuth, and graceful warning fallback on API errors.
  • src/gcp/cloudmonitoring.spec.ts: Listing/creating notification channels and getting/updating alert policies via Cloud Monitoring v3 API.
• Manual E2E testing:
  • Enabled the crashlyticsWebAlerts experiment (firebase experiments:enable crashlyticsWebAlerts) and ran firebase crashlytics:onboard:web against a test Firebase project to verify notification channel creation and alert policy attachment in Cloud Monitoring.