feat: add Source filter to library filtering system (#1131)

* feat: add Source filter to library filtering system

Add a new Source filter section to the library options panel that allows
users to filter their library manga by source (e.g. MangaDex, MangaSee).

- Add hasSource to LibraryOptions type and category metadata
- Add source filtering logic in useGetVisibleLibraryMangas
- Add Source section with three-state checkboxes in filter UI
- Show loading spinner while source list loads
- Include source filter in active filter indicator

Closes #1057

* refactor: address review feedback for source filter

- Remove skip option, let query always run
- Use uniqBy from lodash/fp for deduplication
- Remove loading spinner (data available quickly)
- Wrap source section in length check

* docs: add source filter to changelog

---------

Co-authored-by: Copilot <noreply@github.com>

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Added
 
+- (**Library**) Add source filter to library filtering options
 - (**Migration**) Add a search option to ignore outdated matches
 - (**Migration**) Add a search option to ignore matches with missing chapters
 - (**Migration**) Add "local source" as a possible destination source