feat(identity): web metadata enrichment for titles missing on TMDB (META-1)

- metadata.enrich (propose, low, replay safe): normalized-title cache (kv_cache
  region enrich, 7 days) -> daily budget -> web.search (title + 短剧 / 电视剧 平台,
  second query limited to whitelist via site:) -> web.fetch of up to 3 relevant
  whitelisted pages (registered site domains never read, redirects out of the
  whitelist dropped) -> upstream model extraction with rule fallback -> server-side
  evidence check (rule_confirmed / multi_evidence / needs_review). Suggestion only.
- POST /identity-pool/{id}/enrich (suggest) and /enrich/apply (console session):
  provisional entity or same-title merge, season/episode units, field-level
  metadata with source web/agent + evidence, aliases, release assignment.
  Poster proxy GET /img/enrich/{id} (og:image from whitelisted pages only).
- Auto-enrich once per pool entry when subscription/rule lookups find nothing on
  TMDB (identity.autoEnrich, off by default); identity.enrichDailyBudget,
  identity.enrichDomains settings; web.fetch now returns og:image.
- Pool sheet "元数据补全" section; entity detail shows evidence links.
- Migration 0049_enrichment (metadata_enrichment, metadata_field.evidence, source
  web). Requires image rebuild / api + worker restart to take effect.

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

packages/contracts/src/capability.ts

@@ -89,6 +89,7 @@ export const CAPABILITY_IDS = [
   "agent.propose_options",
   "web.search",
   "web.fetch",
+  "metadata.enrich",
 ] as const;
 export const KnownCapabilityId = z.enum(CAPABILITY_IDS);
 export type KnownCapabilityId = z.infer<typeof KnownCapabilityId>;
@@ -563,6 +564,19 @@ export const CAPABILITY_CATALOG: Record<KnownCapabilityId, CapabilityDescriptor>
     true,
     false,
   ),
+  // META-1:只产出建议(存补全记录,不写作品表);消耗网页搜索次数,受每日预算约束。应用建议走控制台 /identity-pool/{id}/enrich/apply
+  "metadata.enrich": d(
+    "metadata.enrich",
+    "补全元数据",
+    "TMDB 查不到的作品（短剧、平台独播剧）按标题查网页：搜索后只读白名单网站（平台、百科），抽取标题、别名、年份、平台、集数、简介、海报、类型，每个字段带出处和证据等级。只给建议，不改作品；同一标题 7 天内直接返回上次结果",
+    "propose",
+    "MetadataEnrich",
+    "organize.execute",
+    "low",
+    true,
+    false,
+    "safe",
+  ),
 };
 
 function d(