refactor: 架构重组 — doc/bot → core/infra，新增 Agent 调度模块

- src/doc/ 拆分为 src/core/extraction/, matching/, validation/（核心业务逻辑）
- src/bot/ 重命名为 src/infra/browser/（浏览器自动化基础设施）
- fill_consumable_doc.py → src/infra/documents/consumable.py
- 新增 Agent 调度模块：coordinator.py, events.py, session.py，重构 orchestrator.py
- 更新 AGENTS.md、README.md 及所有子目录 README

src/web/static/js/agent.js

@@ -35,6 +35,12 @@ export function handleAgentEvent(msg) {
     case 'agent_force_submit':
       _handleForceSubmit(msg);
       break;
+    case 'agent_max_rounds':
+      _handleAgentError(msg);
+      break;
+    case 'agent_extract_status':
+      _handleAgentStateChange(msg);
+      break;
   }
 }