feat: Add thumbnail generation feature and update media model

- Updated workspace members to include `libertas_importer`.
- Added a new migration to add `thumbnail_path` column to `media` table.
- Enhanced configuration structures to include `thumbnail_config`.
- Modified `Media` model to include `thumbnail_path`.
- Updated `MediaRepository` trait and its implementation to handle thumbnail path updates.
- Created `ThumbnailPlugin` for generating thumbnails based on media configurations.
- Integrated thumbnail generation into the media processing workflow.
- Updated dependencies in `libertas_worker` and `libertas_importer` for image processing.

libertas_api/migrations/20251111220132_thumbnail_path_to_media.sql

@@ -0,0 +1 @@
+ALTER TABLE media ADD COLUMN thumbnail_path VARCHAR(255);