feat(ECR-021): AICoreConfig SystemPrompt 只读并 Closed

新增 system_prompts 目录、admin.ai_config.read 与 admin-h5「AI」页；本切片不改运行时 Prompt、禁写发布/UGC/真支付。

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

proto/openapi.yaml

@@ -527,6 +527,34 @@ paths:
         '200':
           description: OK
 
+  /api/v1/admin/ai/system-prompts:
+    get:
+      tags: [admin]
+      summary: List SystemPrompt catalog
+      description: Requires admin.ai_config.read
+      responses:
+        '200':
+          description: OK
+        '401':
+          description: Unauthorized
+        '403':
+          description: Forbidden
+
+  /api/v1/admin/ai/system-prompts/{id}:
+    get:
+      tags: [admin]
+      summary: Get SystemPrompt
+      parameters:
+        - in: path
+          name: id
+          required: true
+          schema: { type: string, format: uuid }
+      responses:
+        '200':
+          description: OK
+        '404':
+          description: Not found
+
   /api/v1/admin/orders:
     get:
       tags: [admin]