chore: sync local changes, add Chinese docs and opencode config

opencode配置/skill/unified-review/references/specialists/api-contract.md

@@ -0,0 +1,13 @@
+# API Contract Specialist
+
+Focus: API and interface contract changes in the diff.
+
+- [ ] Breaking changes to public endpoints (paths, params, response shape)
+- [ ] Versioning compatibility (deprecations, fallbacks)
+- [ ] Request/response validation matches the schema
+- [ ] Error response shape is consistent
+- [ ] Authentication/authorization behavior unchanged for existing consumers
+- [ ] Renamed/moved functions: all callers updated
+
+Output JSON lines:
+`{"severity":"CRITICAL|INFORMATIONAL","confidence":N,"path":"file","line":N,"category":"api-contract","summary":"...","fix":"...","source":"api-contract"}`