Adds first-class manga metadata across the stack:
- **Status** (ongoing / completed), **alternative titles**, normalized
**multi-author** support, **curated genres** (13 seeded), and
**free-form user tags** (case-insensitive, globally shared). Each is
modelled as its own table joined to mangas; `mangas.author` is
backfilled into `authors` + `manga_authors` and dropped.
- New endpoints: `PATCH /v1/mangas/:id` (three-state `description`),
`POST/DELETE /v1/mangas/:id/tags[/:tag_id]`, `GET /v1/genres`,
`GET /v1/tags?search=`.
- `GET /v1/mangas` now returns `MangaCard` (with authors + genres
batched in) and supports `?status=`, `?author_id=`, `?genre_id=`,
`?tag_id=` filters — AND across facets, with empty-array no-op
semantics for the unnest primitive.
- `GET /v1/mangas/:id` returns the enriched `MangaDetail` with tags.
- Frontend: reusable `Chip` component; manga detail page renders
authors as chips linking to `/authors/:id` (Phase 2), a status
badge, alt titles, genres, and tags with inline add/remove (only
the attacher sees remove); upload form supports multi-author /
multi-genre / alt titles / status; search page gets a collapsible
URL-synced filter panel with keyboard-navigable tag autocomplete.
- 126 backend tests (incl. AND-across-facets primitive, case-insens
author/tag de-dup, transactional create rollback, PATCH semantics
for missing / null / set on description); 72 frontend tests +
svelte-check clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
