feat(contracts,server,web): files G6–G8 fields and identify S-7 contract

- G6: FileRoot.pendingCount/pendingPartial for download roots (same rule as the
  unidentified filter, recursive, cached 5 min, invalidated by files.changed)
- G7: FileEntry.parsedHint from parseReleasePath (file + parent dirs); the web
  subline uses it and no longer parses names itself
- G8: FileIdentifyCandidate.posterUrl (TMDB poster_path via adapter and
  catalog.lookup, local entities from metadata.posterPath); thumbnails in the
  identify panel
- S-7 contract: FilesIdentifyResult.remoteTaskId/remotePending,
  MediaServerInventory.partial, EventType identify.completed with
  IdentifyCompletedPayload; identify panel (useIdentifyLive) and organize wizard
  merge remote results by root + path, buffering events that beat the response

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/contracts/src/capabilities-io.ts

@@ -51,6 +51,8 @@ export const CatalogLookupOutput = z.object({
       externalId: z.string(),
       title: z.string(),
       year: z.number().int().nullable(),
+      /** TMDB poster_path;文件管理识别候选拼海报缩略图 */
+      posterPath: z.string().nullable().optional(),
     }),
   ),
 });