Outcome - Fix Scheduler Concurrency and Browser Stability

Summary

Successfully implemented fixes for the scheduler concurrency issues and browser instability.

Scheduler Configuration Validation:
- Updated src/lib/server/scheduler.ts to validate intervalMinutes.
- Added a check for NaN and a minimum interval of 15 minutes.
- Defaults to 720 minutes if the configuration is invalid.
Resource Cleanup:
- Refactored renewInstagramAuth in src/lib/server/scheduler.ts to use a finally block for closing page and context.
- Ensures resources are released even if an error occurs during renewal.
Robust Browser Management:
- Updated src/lib/server/browser.ts to check browser.isConnected().
- Automatically re-initializes the browser if it is disconnected or crashed.

The scheduler will now default to a safe interval if misconfigured, preventing console spam.
Browser crashes will be automatically recovered from on the next scheduler run.
Resource leaks from failed renewal attempts are prevented.