This major refactor addresses improper image matching and duplication:
- Implemented strict ID-based matching in 'MediaService', removing the greedy filename matching fallback.
- Redesigned synchronization pipeline to treat Google Drive as the Source of Truth, supporting orphan adoption (Shopify -> Drive) and secure uploads.
- Implemented 'gallery_order' using Drive file properties (supporting both v2 and v3 APIs) for stable, drag-and-drop global ordering.
- Added conditional file renaming using timestamps to enforce '_' naming convention without unnecessary renames.
- Fixed runtime errors in 'MediaService' loops and updated 'ShopifyMediaService' GraphQL mutations to match correctly schema.
- Rewrote 'MediaService.test.ts' with robust test cases for strict matching, adoption, sorting, and reordering.
- Implement DriveService and ShopifyMediaService for backend operations
- Create MediaSidebar.html with premium UI and auto-polling
- Integrate Google Picker API for robust file selection
- Orchestrate sync logic via MediaService (Drive -> Staged Upload -> Shopify)
- Add secure config handling for API keys and tokens
- Update ppsscript.json with required OAuth scopes
- Update MEMORY.md and README.md with architecture details
