feat(ECR-017): AskOperations 问答会话只读并 Closed

新增 admin.ask.read、GET /admin/ask/threads*（AskSessionView）与 admin-h5「问答」页；禁改消息/UGC/真支付。

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

docs/CONTRACT_DIFF/ECR-017.yaml

@@ -0,0 +1,23 @@
+ecr: ECR-017
+capability: AskOperations
+bounded_context: Ask_Ops
+parent: WAVE0-FROZEN
+predecessor: ECR-016
+change:
+  type: additive
+breaking_change: false
+migration_required: true
+compatibility_notes: >
+  Additive admin read APIs for AskSessionView.
+  Migration 000019 only grants admin.ask.read to super_admin.
+
+apis:
+  - method: GET
+    path: /api/v1/admin/ask/threads
+    change: added
+  - method: GET
+    path: /api/v1/admin/ask/threads/{id}
+    change: added
+perms:
+  - code: admin.ask.read
+    change: added