feat(ECR-019): ContentSafety FilterRule 只读并 Closed

新增 filter_rules、admin.content_safety.read、列表/详情/试匹配 API 与 admin-h5「安全」页；禁审核写/UGC/真支付。

Co-authored-by: Cursor <cursoragent@cursor.com>

.ai/product/feature-spec/README.md

@@ -28,6 +28,7 @@
 | [ops-user-intelligence.md](ops-user-intelligence.md) | 用户洞察 UserIntelligence | §7 | `admin-h5` 用户详情「洞察」· `GET /admin/users/:id/insight` | Ops-D · **ECR-016 Closed** |
 | [ops-ask-operations.md](ops-ask-operations.md) | 问答运营 AskOperations | §7 | `admin-h5` `/ask` · `GET /admin/ask/threads*` | Ops-D · **ECR-017 Closed** |
 | [ops-entitlement.md](ops-entitlement.md) | 用户权益 Entitlement | §7 | `admin-h5` 用户详情「权益」· `GET /admin/users/:id/entitlements` | Ops-D · **ECR-018 Closed** |
+| [ops-content-safety.md](ops-content-safety.md) | 内容安全 ContentSafety | §7 | `admin-h5` `/safety` · `GET /admin/content-safety/*` | Ops-D · **ECR-019 Closed** |
 
 新功能：复制 `_TEMPLATE.md` → 填满 → 在本表登记 → 再编码。