feat(req): REQ 连续推进（continuous）模式 + checkpoint

- 新增 req-workflow/skills/references/continuous-mode.md：阶段自动循环、hard/soft 门禁分级、checkpoint schema、恢复协议、停止格式、staging 终点约定
- req / req-workflow SKILL.md 增加 continuous 小节与门禁分级说明
- 版本号、CHANGELOG、docs/skill-routing.md、catalog.json 同步

catalog.json

@@ -7,7 +7,7 @@
     "missing_evals": [],
     "missing_docs": []
   },
-  "generated_at": "2026-10-31T21:33:50Z",
+  "generated_at": "2026-11-01T01:55:45Z",
   "total": 62,
   "counts": {
     "promoted/user-invoked": 18,
@@ -710,13 +710,13 @@
     {
       "name": "req",
       "category": "req",
-      "version": "2.1.0",
+      "version": "2.2.0",
       "status": "promoted",
       "invocation": "model-invoked",
       "description": "需求工作流管理。用于 /req 命令使用、需求全生命周期管理（创建→PRD→评审→开发→测试→部署→归档）。当用户提到需求管理、/req 命令、REQ-XXX 相关任务时自动激活。",
       "description_len": 90,
       "path": "skills-req/req-plugin/skills/SKILL.md",
-      "digest": "193cf871b73faff1",
+      "digest": "1ba369ef4a51c0c7",
       "has_evals": true,
       "has_docs": true
     },
@@ -801,13 +801,13 @@
     {
       "name": "req-workflow",
       "category": "req",
-      "version": "1.0.0",
+      "version": "1.1.0",
       "status": "promoted",
       "invocation": "model-invoked",
       "description": "需求完整工作流。用于从创建到归档的完整流程、Hook 自动同步、测试环境流程。当需要了解需求完整生命周期或同步策略时使用。",
       "description_len": 61,
       "path": "skills-req/req-workflow-plugin/skills/SKILL.md",
-      "digest": "87499da3817d162d",
+      "digest": "74ec85536d97b8c9",
       "has_evals": true,
       "has_docs": true
     },