feat: 后台任务系统 + JSON容错解析 + SSE心跳保活 + 多项Bug修复

新功能:
- 大纲/章节生成改为服务端后台任务，支持断线续传
- 后台任务队列排队执行，按用户排队（同用户串行不同用户并发）
- 章节管理页面添加后台任务列表弹窗和进度面板
- 章节状态添加 pending（待处理）选项
- 集成json5容错解析器 + 上下文感知JSON修复
- SSE流式生成添加心跳保活，防止连接超时
- SSEPostClient添加credentials:include修复network error
- 每章最大伏笔数从2调整为5
- 添加大纲读区伏笔的功能

Bug修复:
- 修复AI生成JSON中未转义引号/中文标点/多对象属性值未合并
- 修复JSON非法转义字符清洗和中文引号处理
- 修复MCP插件TimeoutError/连接失败上下文清理
- MCP插件后台注册添加重试机制
- 续写模式添加缺失的mcp_references参数
- 修复Alembic迁移链分叉
- 使用torch CPU版本加速Docker构建

frontend/pnpm-lock.yaml

@@ -23,6 +23,9 @@ importers:
       '@types/canvas-confetti':
         specifier: ^1.9.0
         version: 1.9.0
+      '@types/dagre':
+        specifier: ^0.7.54
+        version: 0.7.54
       '@xyflow/react':
         specifier: ^12.10.1
         version: 12.10.1(@types/react@18.3.28)(react-dom@18.3.1(react@18.3.1))(react@18.3.1)
@@ -35,6 +38,9 @@ importers:
       canvas-confetti:
         specifier: ^1.9.4
         version: 1.9.4
+      dagre:
+        specifier: ^0.8.5
+        version: 0.8.5
       dayjs:
         specifier: ^1.11.13
         version: 1.11.19
@@ -734,6 +740,9 @@ packages:
   '@types/d3-zoom@3.0.8':
     resolution: {integrity: sha512-iqMC4/YlFCSlO8+2Ii1GGGliCAY4XdeG748w5vQUbevlbDu0zSjH/+jojorQVBK/se0j6DUFNPBGSqD3YWYnDw==}
 
+  '@types/dagre@0.7.54':
+    resolution: {integrity: sha512-QjcRY+adGbYvBFS7cwv5txhVIwX1XXIUswWl+kSQTbI6NjgZydrZkEKX/etzVd7i+bCsCb40Z/xlBY5eoFuvWQ==}
+
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
@@ -996,6 +1005,9 @@ packages:
     resolution: {integrity: sha512-b8AmV3kfQaqWAuacbPuNbL6vahnOJflOhexLzMMNLga62+/nh0JzvJ0aO/5a5MVgUFGS7Hu1P9P03o3fJkDCyw==}
     engines: {node: '>=12'}
 
+  dagre@0.8.5:
+    resolution: {integrity: sha512-/aTqmnRta7x7MCCpExk7HQL2O4owCT2h8NT//9I1OQ9vt29Pa0BzSAkR5lwFUcQ7491yVi/3CXU9jQ5o0Mn2Sw==}
+
   dayjs@1.11.19:
     resolution: {integrity: sha512-t5EcLVS6QPBNqM2z8fakk/NKel+Xzshgt8FFKAn+qwlD1pzZWxh0nVCrvFK7ZDb6XucZeF9z8C7CBWTRIVApAw==}
 
@@ -1200,6 +1212,9 @@ packages:
     resolution: {integrity: sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==}
     engines: {node: '>= 0.4'}
 
+  graphlib@2.1.8:
+    resolution: {integrity: sha512-jcLLfkpoVGmH7/InMC/1hIvOPSUh38oJtGhvrOFGzioE1DZ+0YW16RgmOJhHiuWTvGiJQ9Z1Ik43JvkRPRvE+A==}
+
   has-flag@4.0.0:
     resolution: {integrity: sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==}
     engines: {node: '>=8'}
@@ -1299,6 +1314,9 @@ packages:
   lodash.merge@4.6.2:
     resolution: {integrity: sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==}
 
+  lodash@4.18.1:
+    resolution: {integrity: sha512-dMInicTPVE8d1e5otfwmmjlxkZoUpiVLwyeTdUsi/Caj/gfzzblBcCE5sRHV/AsjuCmxWrte2TNGSYuCeCq+0Q==}
+
   loose-envify@1.4.0:
     resolution: {integrity: sha512-lyuxPGr/Wfhrlem2CL/UcnUc1zcqKAImBDzukY7Y5F/yQiNdko6+fRLevlw1HgMySw7f611UIY408EtxRSoK3Q==}
     hasBin: true
@@ -2498,6 +2516,8 @@ snapshots:
       '@types/d3-interpolate': 3.0.4
       '@types/d3-selection': 3.0.11
 
+  '@types/dagre@0.7.54': {}
+
   '@types/estree@1.0.8': {}
 
   '@types/json-schema@7.0.15': {}
@@ -2861,6 +2881,11 @@ snapshots:
       d3-selection: 3.0.0
       d3-transition: 3.0.1(d3-selection@3.0.0)
 
+  dagre@0.8.5:
+    dependencies:
+      graphlib: 2.1.8
+      lodash: 4.18.1
+
   dayjs@1.11.19: {}
 
   debug@4.4.3:
@@ -3082,6 +3107,10 @@ snapshots:
 
   gopd@1.2.0: {}
 
+  graphlib@2.1.8:
+    dependencies:
+      lodash: 4.18.1
+
   has-flag@4.0.0: {}
 
   has-symbols@1.1.0: {}
@@ -3158,6 +3187,8 @@ snapshots:
 
   lodash.merge@4.6.2: {}
 
+  lodash@4.18.1: {}
+
   loose-envify@1.4.0:
     dependencies:
       js-tokens: 4.0.0