feat(server): W2-B sources, identity resolution, metadata and site workbench

- Sites / accounts / feeds: registry view (/site-definitions), site CRUD with
  enable/disable (history stays queryable, marked site_disabled), accounts and
  feed URLs stored as secrets (only secret_ref / redacted urlDisplay exposed),
  feed enable/disable/reset/fetch; one shared rate limiter + adapter per site.
- Tasks: ingestFeed (FeedFetchState/FeedCursor on feed_source, observation
  feed+guid upsert with digest-change updates, source_release site+id
  aggregation across feeds, auth failure -> account invalid + decision, no
  retry, gap -> feed.gap_suspected -> budgeted backfill snapshot),
  resolveObservation (parseRelease -> local recall via title_alias pg_trgm +
  accepted identities -> TMDB -> resolveIdentity; auto binds entity /
  provisional units / identities / aliases, otherwise identity_candidate pool
  with evidence version and bounded review backoff; manual lock respected),
  refreshMetadata (metadata_field + field_override, user locks win, paths
  untouched), snapshotSite (site_snapshot coverage records).
- Events: feed.due, feed.gap_suspected, release.observed (self-consumed),
  release.resolved, decision.created/updated; scheduler in worker start().
- Identity API: entity detail with redirects, manual mapping correction with
  identity_revision, merge with identity_redirect, pool list/assign/dismiss/
  retry, content unit numbering lock, aliases, external identities.
- Decisions: list/summary (by entity and kind)/detail/resolve; identity
  options executed directly.
- Workbench: /sites/{id}/releases (snapshot first, coalesced live search with
  backoff, origin + freshness) and /sites/{id}/releases/{rid} (volatile field
  recheck times, refresh keeps data on failure).
- Capabilities: catalog.lookup, release.search, release.inspect,
  identity.resolve.
- Migrations 0018-0020: site.adapter api, source_release.resolution_locked,
  site_snapshot, identity_candidate, resolution_attempt, identity_redirect,
  metadata_field, field_override.

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

packages/contracts/src/content.ts

@@ -1,5 +1,6 @@
 import { z } from "zod";
-import { DateOnly, EntityBase, Id, JsonObject, SERVER_MANAGED, Timestamp } from "./common.ts";
+import { ActorType, DateOnly, EntityBase, Id, JsonObject, SERVER_MANAGED, Timestamp } from "./common.ts";
+import { ExternalIdentity } from "./identity.ts";
 
 // 内容域:本地作品、内容单元、别名(REQ §3.1、§5.1、§5.4、§7.5)
 // 本地 UUID 是主身份;季/集编号、外部 ID 都可修订,不是唯一身份。
@@ -127,3 +128,82 @@ export const TitleAliasCreate = TitleAlias.pick({
 export type TitleAliasCreate = z.infer<typeof TitleAliasCreate>;
 export const TitleAliasUpdate = TitleAliasCreate.omit({ mediaEntityId: true }).partial();
 export type TitleAliasUpdate = z.infer<typeof TitleAliasUpdate>;
+
+// ── W2-B:字段级元数据(REQ §7.3)与作品详情 ──
+
+export const MetadataSource = z.enum(["tmdb", "user", "agent", "nfo", "site", "import"]);
+export type MetadataSource = z.infer<typeof MetadataSource>;
+
+/** 某来源给出的一个候选字段值(刷新只写这里,不直接改最终展示值) */
+export const MetadataField = EntityBase.extend({
+  mediaEntityId: Id.nullable(),
+  contentUnitId: Id.nullable(),
+  field: z.string().min(1),
+  value: z.unknown(),
+  language: z.string().nullable(),
+  source: MetadataSource,
+  sourceRevision: z.string().nullable(),
+  fetchedAt: Timestamp,
+});
+export type MetadataField = z.infer<typeof MetadataField>;
+
+/** 字段覆盖:用户锁定优先于任何自动刷新 */
+export const FieldOverride = EntityBase.extend({
+  mediaEntityId: Id.nullable(),
+  contentUnitId: Id.nullable(),
+  field: z.string().min(1),
+  value: z.unknown(),
+  locked: z.boolean(),
+  source: MetadataSource,
+  reason: z.string().nullable(),
+  actorType: ActorType,
+  actorId: z.string().nullable(),
+});
+export type FieldOverride = z.infer<typeof FieldOverride>;
+
+/** 可覆盖/锁定的作品字段;title/originalTitle/year 同时投影到 media_entity 列 */
+export const EntityMetadataField = z.enum([
+  "title",
+  "originalTitle",
+  "year",
+  "overview",
+  "releaseDate",
+  "originalLanguage",
+  "originCountry",
+  "posterPath",
+]);
+export type EntityMetadataField = z.infer<typeof EntityMetadataField>;
+
+export const FieldOverrideInput = z.object({
+  value: z.unknown(),
+  lock: z.boolean().default(true),
+  reason: z.string().max(2000).optional(),
+});
+export type FieldOverrideInput = z.infer<typeof FieldOverrideInput>;
+
+/** media_entity.metadata 中每个最终字段的形状 */
+export const FinalFieldValue = z.object({
+  value: z.unknown(),
+  source: MetadataSource,
+  language: z.string().nullable(),
+  at: Timestamp,
+  locked: z.boolean(),
+});
+export type FinalFieldValue = z.infer<typeof FinalFieldValue>;
+
+/** 作品详情:外部身份、别名、内容单元、字段来源与覆盖 */
+export const MediaEntityDetail = z.object({
+  entity: MediaEntity,
+  /** 请求的是已合并的旧 ID 时,指向跳转后的实体 */
+  redirectedFrom: Id.nullable(),
+  identities: z.array(ExternalIdentity),
+  aliases: z.array(TitleAlias),
+  contentUnits: z.array(ContentUnit),
+  metadataFields: z.array(MetadataField),
+  overrides: z.array(FieldOverride),
+});
+export type MediaEntityDetail = z.infer<typeof MediaEntityDetail>;
+
+/** 合并重复作品(保留旧 ID 跳转) */
+export const MediaEntityMerge = z.object({ intoId: Id, reason: z.string().max(2000).optional() });
+export type MediaEntityMerge = z.infer<typeof MediaEntityMerge>;