feat(identity): trust site-provided IMDb/TMDB IDs in scoring (ID-3)

MatchOptions.trustedIds: a candidate fetched by a site-given ID is at least
multi_evidence even when titles differ; year/type conflicts stay candidates.
Differential group site-ids-* against MP search/result.py _match_source.

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

packages/domain/test/differential/identity/site-ids-deviations.json

@@ -0,0 +1,13 @@
+{
+  "note": "ID-3 站点外部 ID 组的逐条归因。MP `_match_source` 只要种子 IMDb 与作品一致就判命中;我们把站点 ID 当强证据但保留年份 / 类型硬规则。",
+  "deviations": {
+    "S-004": {
+      "kind": "intentional",
+      "note": "年份差 37 年:站点 IMDb 链接挂错(挂到同名新片)的典型。我们只作候选(needs_confirm → 待确认),不自动绑定;MP 直接按 IMDb 命中"
+    },
+    "S-006": {
+      "kind": "intentional",
+      "note": "剧集标题(S01)配电影 IMDb:类型冲突,只作候选;MP 按 IMDb 命中"
+    }
+  }
+}