[OPS] Add Application Insights alert for LinkedIn token refresh failures

[artcava]

Overview

Add a dedicated Application Insights alert rule that fires when LinkedInTokenRefresherFunction logs an error, ensuring immediate notification if the auto-refresh fails and manual intervention is needed before the token expires.

Depends on: #58

Tasks

• Create alert rule in Application Insights targeting LinkedInTokenRefresher function errors:

traces
| where timestamp > ago(2h)
| where message contains "LinkedIn token refresh"
| where severityLevel >= 3

• Configure action group: email notification to cavallo.marco@gmail.com
• Alert severity: Sev 1 – Error (token expiry is a hard blocker for LinkedIn publishing)
• Evaluation frequency: every 5 minutes, lookback window: 2 hours
• Add Bicep snippet to docs/monitoring.md for IaC reproducibility
• Test alert by manually triggering a failure (e.g., temporarily invalidating the refresh token in Key Vault)

Acceptance Criteria

• Email received within 10 minutes of a refresh failure
• Alert auto-resolves when next successful refresh occurs
• Bicep snippet documented in docs/monitoring.md

References

• Analysis document — Section 5, Step 6
• docs/monitoring.md

[github-actions]

👋 Thanks for opening this issue! A maintainer will review it soon and label it as approved if it can proceed to development.

[artcava]

Deferred

This issue is blocked and deferred until the LinkedIn token refresh strategy is unblocked.

This alert monitors failures of LinkedInTokenRefresherFunction (#58), which itself depends on #56 and #57. Since the entire refresh chain is blocked pending availability of a valid refresh_token, there is nothing to monitor yet.

See #56 for the full reasoning behind this deferral decision. This issue will be re-evaluated once #56, #57, and #58 are unblocked.