feat: OpenMesh 基础平台与 MD/PDF 转换技能

- 后端: coworker 智能体框架, WS API, 文件上传, 附件处理
- 前端: Open WebUI, 文件全量走 upload API (含 MD/TXT/JSON 等文本类)
- 技能: md-to-office (pandoc + wkhtmltopdf)
- 修复: 上传文件路径丢失, Agent 搜索浪费, 输出文件跑到 uploads/
- 打包: PyInstaller one-dir, 预打包 pandoc/wkhtmltopdf/chromium

coworker/automation/__init__.py

@@ -0,0 +1,18 @@
+"""Automation — scheduled tasks that run in the always-on server."""
+
+from __future__ import annotations
+
+from .models import Schedule, ScheduledTask, TaskRun
+from .scheduler import Scheduler
+from .store import TaskStore, compute_next_run
+from .tools import scheduling_tools
+
+__all__ = [
+    "Schedule",
+    "ScheduledTask",
+    "TaskRun",
+    "Scheduler",
+    "TaskStore",
+    "compute_next_run",
+    "scheduling_tools",
+]