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]>

apps/web/app/api/files.ts

@@ -56,6 +56,7 @@ export type {
   FileRef,
   FileRoot,
   FileStatus,
+  FilesIdentifyResult,
   FilesOnExisting,
   FilesOrganizeGroup,
   FilesOrganizeItem,
@@ -64,6 +65,7 @@ export type {
   FilesSuggestNameResult,
   FilesTransferResult,
   FilesTreeResult,
+  IdentifyCompletedPayload,
   NamingTemplateSource,
   TmdbCandidate,
   TrashItem,