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/tools/directories.py

@@ -0,0 +1,45 @@
+"""The `request_directory` tool — the agent asks the user to grant access to a folder.
+
+Unlike ordinary tools, this one is intercepted by the TurnEngine: it emits a DIRECTORY_REQUESTED
+event and waits for the user to pick/approve a folder out-of-band (the GUI surfaces a prompt),
+then the live session gains that root and the tool result tells the agent the outcome. The
+callable here is only a schema carrier + a safe fallback for surfaces without a requester.
+"""
+
+from __future__ import annotations
+
+from aisuite.agents import ToolMetadata, tool
+
+
+def request_directory_tool() -> object:
+    def request_directory(
+        reason: str, path: str = "", writable: bool = False, primary: bool = False
+    ) -> dict:
+        """Ask the user for access to a directory when the task needs files outside the current
+        ones (e.g. to read a project the user mentioned, or to save a deliverable somewhere
+        specific). Explain why in `reason`; optionally suggest a `path` and whether you need
+        `writable` access. Set `primary=true` only when the granted folder should become the
+        session's main workspace (the project the whole conversation is about) — allowed once,
+        and only while the session is still running on its scratch directory. The user
+        picks/approves the folder; the result says whether it was granted. Do not use this to
+        escape sandboxing — only to serve the user's request.
+        """
+        # Real handling lives in the engine (it needs the out-of-band GUI round-trip). This body
+        # only runs if no requester is wired (e.g. a headless surface).
+        return {
+            "granted": False,
+            "error": "directory requests aren't available in this surface",
+        }
+
+    return tool(
+        request_directory,
+        metadata=ToolMetadata(
+            category="filesystem",
+            risk_level="low",
+            capabilities=["request_directory"],
+            description=(
+                "Ask the user to grant access to a directory (read-only or read-write) when the "
+                "task needs files outside the directories you already have."
+            ),
+        ),
+    )