New Features
4- Added Docker Stacks tab in Docker Manager with stack list table showing container count, volume, network, and DB type badge
- Stack backup button with SSE progress modal displaying phase, percentage, and live messages
- Stack restore modal with drag-and-drop file upload and SSE progress tracking
- Backup history table with download and delete actions
Improvement
1- Added fetchSSE() helper for POST-based Server-Sent Events (EventSource only supports GET)