feat: AniList reading status integration

- Add full AniList integration: OAuth connect, series linking, push/pull sync
- Push: PLANNING/CURRENT/COMPLETED based on books read vs total_volumes (never auto-complete from owned books alone)
- Pull: update local reading progress from AniList list (per-user)
- Detailed sync/pull reports with per-series status and progress
- Local user selector in settings to scope sync to a specific user
- Rename "AniList" tab/buttons to generic "État de lecture" / "Reading status"
- Make Bédéthèque and AniList badges clickable links on series detail page
- Fix ON CONFLICT error on series link (provider column in PK)
- Migration 0054: fix series_metadata missing columns (authors, publishers, locked_fields, total_volumes, status)
- Align button heights on series detail page; move MarkSeriesReadButton to action row

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/backoffice/app/components/MetadataSearchModal.tsx

@@ -683,13 +683,6 @@ export function MetadataSearchModal({
         {existingLink && existingLink.status === "approved" ? t("metadata.metadataButton") : t("metadata.searchButton")}
       </button>
 
-      {existingLink && existingLink.status === "approved" && (
-        <span className="inline-flex items-center gap-1 px-2 py-0.5 rounded-full bg-primary/10 text-primary text-xs border border-primary/30">
-          <ProviderIcon provider={existingLink.provider} size={12} />
-          <span>{providerLabel(existingLink.provider)}</span>
-        </span>
-      )}
-
       {modal}
     </>
   );