v1.0.8-beta.021 - refactor: overhaul weekly digest tracking and fix email attachments
- Migrated Weekly Digest history from a JSON string setting to a dedicated DigestHistory relational database table for better scalability and performance.
- Implemented a 14-day rolling cleanup mechanism for the digest ledger to prevent infinite database growth.
- Capped the weekly digest email at 15 series to prevent exceeding provider attachment limits (e.g., Gmail's 25MB limit).
- Fixed broken cover art in emails by explicitly embedding images as inline CID attachments with unique cryptographic hashes to bypass client deduplication.
- Updated the automated backup and restore API routes to include the new DigestHistory table.
- Resolved TypeScript compilation errors in the admin settings UI and mailer utility.