feat: enable weekly digest emails for production (SPRW-3110)

[mayankjha-eng]

Description

Implemented weekly digest email functionality for production. Emails are now scheduled to run every Monday at 8 AM (IST) and include accurate weekly metrics with proper week-over-week comparison.

Key updates:

• Enabled cron job for weekly execution in production only
• Updated date logic to use last completed week for accurate reporting
• Ensured correct comparison with previous week data
• Removed development/testing email overrides
• Finalized email content with user metrics, activity trends, and updates

Add Issue Number

Fixes #<your_issue_number>

Add Screenshots/GIFs

If applicable, add relevant screenshot/gif here.

Add Known Issue

If applicable, add any known issues.

Contribution Checklist:

• The pull request only addresses one issue or adds one feature.
• I have linked an issue to the pull request.
• I have linked a PR type label to the pull request.
• The pull request does not introduce any breaking changes
• I have added screenshots or gifs to help explain the change if applicable.
• I have read the contribution guidelines.

Note: Keeping the PR small and focused helps make it easier to review and merge. If you have multiple changes you want to make, please consider submitting them as separate pull requests.