feat(identity): source-aware short-drama enrichment with snippet mode and hit rate (META-2)

- classify enrich sources: encyclopedia, platform pages (hongguo, kuaikaw, video
  platforms), douban (search snippet only) and other sites' search snippets
  (snippet mode, pages never opened); one extractor per source, fields carry
  source kind and confidence, merged by noisy-OR across hosts
- new cast field (applied as MediaCredit with placeholder ids)
- robots.txt check (cached per host 1 day) and login-wall/captcha give-up
- per-enrichment source attempts + GET /identity/enrich-stats, 30-day hit-rate
  table under settings -> metadata -> identity
- setting identity.enrichSnippetAllSites (default on); default domains add
  baike.com and kuaikaw.cn
- replay fixtures from the real run on the 4 user-library short dramas
  (sanitized Brave responses, hongguo page, robots.txt)

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

apps/web/app/api/identity.ts

@@ -4,6 +4,7 @@ import {
   type EnrichApplyInput,
   EnrichApplyResult,
   type EnrichRequest,
+  EnrichStats,
   ExternalIdentity,
   type IdentityCandidateReason,
   type IdentityCandidateStatus,
@@ -28,6 +29,7 @@ export const identityKeys = {
   identities: (f: IdentityFilters) => ["identity", "external", f] as const,
   revisions: (id: string) => ["identity", "revisions", id] as const,
   aliases: (f: AliasFilters) => ["identity", "aliases", f] as const,
+  enrichStats: (days: number) => ["identity", "enrich-stats", days] as const,
 };
 
 export type PoolFilters = { status?: IdentityCandidateStatus; reason?: IdentityCandidateReason; q?: string };
@@ -159,6 +161,15 @@ export function useDeleteAlias() {
   });
 }
 
+/** 元数据补全命中率(最近 N 天,按来源类别;META-2) */
+export function useEnrichStats(days = 30) {
+  return useQuery({
+    queryKey: identityKeys.enrichStats(days),
+    queryFn: ({ signal }) => getParsed(EnrichStats, "/identity/enrich-stats", { days }, signal),
+    staleTime: 60_000,
+  });
+}
+
 /** 元数据补全建议(metadata.enrich;不改作品,同一标题 7 天内返回上次结果) */
 export function useEnrichPool() {
   return useMutation({