feat: 模块化命令框架 + runbook 严格断言与查询结果回传

- core/module: 命令模板、门控（feature flag/confirm/dry-run）、ecode 错误标签、ResultFormatter
- runbook executor: http.get/http.post/assert.json(expect_success 严格断言)、目标主机管理、任务落库、最终 stdout 直接回传
- cf 模块: /cf dns list 支持域名自动解析 zone_id；dns list/zones/workers list 格式化回传；API success:false 判真失败
- 全部 CF/CPA runbook 接入严格断言，杜绝假阳性 success
- 新增 cpa/cfdav/mail/sub 模块与 runbooks；QQ 订阅到期提醒调度
- Web 后台: 模块设置(CF/CPA/cfdav/AI)、OPS 任务、渠道管理、审计页

runbooks/cpa_status.yaml

@@ -0,0 +1,20 @@
+version: 1
+name: cpa_status
+description: 获取 CPA 服务状态与 usage 快照
+inputs: []
+steps:
+  - id: usage_snapshot
+    action: shell.exec
+    on_fail: stop
+    with:
+      command: "CPA_TOKEN=${env.cpa_management_token} CPA_BASE=https://cpa.pao.xx.kg/v0/management python3 -c 'import base64,os; code=base64.b64decode(\"Y3VybCAtc1MgLUggIkF1dGhvcml6YXRpb246IEJlYXJlciAke0NQQV9UT0tFTn0iICR7Q1BBX0JBU0V9L3VzYWdlIHwgcHl0aG9uMyAtYyAiaW1wb3J0IGpzb24sc3lzOyBkYXRhPWpzb24ubG9hZChzeXMuc3RkaW4pOyBvdXQ9eyd1c2FnZSc6IHsndG90YWxfcmVxdWVzdHMnOiBkYXRhLmdldCgndXNhZ2UnLHt9KS5nZXQoJ3RvdGFsX3JlcXVlc3RzJyksICd0b3RhbF90b2tlbnMnOiBkYXRhLmdldCgndXNhZ2UnLHt9KS5nZXQoJ3RvdGFsX3Rva2VucycpfX07IHByaW50KGpzb24uZHVtcHMob3V0LCBlbnN1cmVfYXNjaWk9RmFsc2UpKSIK\"); os.system(code.decode())'"
+
+  - id: usage_assert
+    action: assert.json
+    on_fail: stop
+    with:
+      source_step: usage_snapshot
+      expect_success: true
+      required_paths:
+        - "usage.total_requests"
+        - "usage.total_tokens"