feat(ECR-043): StarConfig 写面闭环并 Closed

加法权限 admin.explore.write、POST/PUT+审计、C端 GET /star/configs、
H5 无 active 空态/失败回退；migration 000052。ExploreConfig Loop STOP，禁自动 ECR-044。

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

docs/CONTRACT_DIFF/ECR-043.yaml

@@ -0,0 +1,20 @@
+ecr: ECR-043
+capability: ExploreConfig
+change:
+  type: additive
+breaking_change: false
+migration_required: true
+apis:
+  - method: POST
+    path: /api/v1/admin/explore/star-configs
+    change: added
+  - method: PUT
+    path: /api/v1/admin/explore/star-configs/{id}
+    change: added
+  - method: GET
+    path: /api/v1/star/configs
+    change: added
+perms:
+  - code: admin.explore.write
+    change: added
+migration: 000052_ops_star_config_write