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]>

apps/server/test/sources-identity/site-capabilities.test.ts

@@ -15,8 +15,8 @@ const TiB = 1024 ** 4;
 const SITE_IDS = ["site.list", "site.health_check", "site.refresh_login", "site.user_data"] as const;
 
 describe("站点能力规格", () => {
-  it("进入首批能力目录(17 + 3 只读摘要 + 4 站点 + 10 浏览器 + 2 会话交互 + 2 网页搜索 = 38);类别 / 风险 / 重放按约定", () => {
-    expect(CAPABILITY_IDS).toHaveLength(38);
+  it("进入首批能力目录(17 + 3 只读摘要 + 4 站点 + 10 浏览器 + 2 会话交互 + 2 网页搜索 + 1 元数据补全 = 39);类别 / 风险 / 重放按约定", () => {
+    expect(CAPABILITY_IDS).toHaveLength(39);
     for (const id of SITE_IDS) expect(CAPABILITY_IDS).toContain(id);
     expect(capabilitySpec("site.list")).toMatchObject({ kind: "read", riskLevel: "low", replay: "safe" });
     expect(capabilitySpec("site.user_data")).toMatchObject({ kind: "read", riskLevel: "low", replay: "safe" });