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/infra/documents/__init__.py

@@ -0,0 +1,32 @@
+"""文档处理基础设施
+
+提供发票数据模型、PDF 渲染、出库单填写等功能。
+"""
+
+from .consumable import (
+    CONSUMABLE_DOC_FILENAME,
+    fill_consumable_doc,
+    fill_consumable_from_template,
+)
+from .invoice import (
+    CACHE_DIR_NAME,
+    classify_invoice_batch,
+    load_csv,
+    load_invoice_csv,
+    save_application_json,
+    save_csv,
+    save_invoice_csv,
+)
+
+__all__ = [
+    "CACHE_DIR_NAME",
+    "classify_invoice_batch",
+    "load_csv",
+    "load_invoice_csv",
+    "save_csv",
+    "save_invoice_csv",
+    "save_application_json",
+    "CONSUMABLE_DOC_FILENAME",
+    "fill_consumable_doc",
+    "fill_consumable_from_template",
+]