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/web/app/components/settings/metadata.tsx

@@ -200,15 +200,44 @@ const IDENTITY_CARD: CardSpec = {
       kind: "number",
       hint: "未命中订阅的条目超过这么多天没有新证据就归档，仍可筛出并手动指定",
     },
+    {
+      name: "identity.autoEnrich",
+      label: "TMDB 查不到时自动补全元数据",
+      kind: "switch",
+      hint: "资源命中订阅或新作品收录规则、TMDB 却没有结果时，自动搜索网页出一份补全建议（每条资源一次，不建作品）。每次约 1–2 次网页搜索、最多读 3 个网页、1 次 Agent 上游调用",
+      wide: true,
+    },
+    {
+      name: "identity.enrichDailyBudget",
+      label: "元数据补全每日上限",
+      kind: "number",
+      hint: "手动和自动合计；7 天内同一标题直接用上次结果，不计次。0 = 停用",
+    },
+    {
+      name: "identity.enrichDomains",
+      label: "补全可读取的网站",
+      kind: "textarea",
+      hint: "每行一个域名，含子域名；只放平台和百科类网站。已登记站点的域名一律不读",
+      wide: true,
+    },
   ],
   fromSettings: (s) => ({
     "identity.eagerTmdbLookup": s.identity.eagerTmdbLookup,
     "identity.poolArchiveDays": n(s.identity.poolArchiveDays),
+    "identity.autoEnrich": s.identity.autoEnrich,
+    "identity.enrichDailyBudget": n(s.identity.enrichDailyBudget),
+    "identity.enrichDomains": s.identity.enrichDomains.join("\n"),
   }),
   toPatch: (v) => ({
     identity: {
       eagerTmdbLookup: v["identity.eagerTmdbLookup"] === true,
       poolArchiveDays: Number(v["identity.poolArchiveDays"]),
+      autoEnrich: v["identity.autoEnrich"] === true,
+      enrichDailyBudget: Number(v["identity.enrichDailyBudget"]),
+      enrichDomains: String(v["identity.enrichDomains"] ?? "")
+        .split(/[\s,，]+/)
+        .map((d) => d.trim().toLowerCase())
+        .filter(Boolean),
     },
   }),
 };