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/toolreq.py

@@ -0,0 +1,52 @@
+"""The `request_tool` tool — the agent asks the user for a CLI it needs but can't find.
+
+Sibling of `request_directory`: the TurnEngine intercepts it, emits TOOL_REQUESTED, and the
+user decides out-of-band (install the pinned build, or skip and let the run continue
+degraded). The callable here is only a schema carrier + the fallback for surfaces with no
+requester wired.
+
+This exists because of a specific failure mode (OPE-85): with gitleaks absent, a security
+review silently dropped its git-history secret scan — the check didn't fail, it vanished
+from the report. A missing tool must become a visible decision, never an invisible gap.
+"""
+
+from __future__ import annotations
+
+from aisuite.agents import ToolMetadata, tool
+
+
+def request_tool_tool() -> object:
+    def request_tool(name: str, reason: str) -> dict:
+        """Ask the user to install one of the PINNED catalog tools you need but can't find
+        on this machine. The catalog is a small closed set — currently `gitleaks`,
+        `trivy`, `osv-scanner` — installed at a pinned, checksum-verified version.
+
+        For ANY other missing CLI (semgrep, jq, kubectl, …) do NOT use this tool: install
+        it yourself with the shell (brew/pip/…), which goes through the normal command
+        approval, or proceed without it.
+
+        Keep `reason` to ONE sentence: which check needs the tool. The prompt the user
+        sees already explains what the install is (pinned version, publisher, checksum)
+        and what happens if they decline — don't restate any of that in `reason`.
+
+        Use this INSTEAD of quietly skipping a check. If the user declines, carry on with a
+        fallback (e.g. reading git history yourself instead of running gitleaks) and state
+        plainly in your report which checks were degraded and why.
+        """
+        return {
+            "installed": False,
+            "error": "tool requests aren't available in this surface",
+        }
+
+    return tool(
+        request_tool,
+        metadata=ToolMetadata(
+            category="system",
+            risk_level="low",
+            capabilities=["request_tool"],
+            description=(
+                "Ask the user to install a missing command-line tool, rather than silently "
+                "skipping the check that needs it."
+            ),
+        ),
+    )