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/events.py

@@ -0,0 +1,49 @@
+"""Event model — the contract between the turn engine and any surface (TUI/GUI/IDE).
+
+No token streaming in v1, so granularity is per-message/per-tool. Streaming later adds
+`assistant_delta` / `tool_output_delta` without changing the rest.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from enum import Enum
+from typing import Any
+
+
+class EventType(str, Enum):
+    TURN_START = "turn_start"
+    ASSISTANT_DELTA = "assistant_delta"
+    REASONING_DELTA = "reasoning_delta"  # model thinking text (display-only, never replayed)
+    ASSISTANT_MESSAGE = "assistant_message"
+    TOOL_PROPOSED = "tool_proposed"
+    PERMISSION_REQUIRED = "permission_required"
+    DIRECTORY_REQUESTED = "directory_requested"  # agent asks the user to grant a folder
+    TOOL_REQUESTED = "tool_requested"  # agent asks for a missing CLI tool (scanner, etc.)
+    QUESTION_REQUESTED = (
+        "question_requested"  # agent asks the user a free-text/multiple-choice question
+    )
+    PLAN_PROPOSED = (
+        "plan_proposed"  # agent presents a plan for approval (plan mode exit)
+    )
+    TEAM_PROPOSED = (
+        "team_proposed"  # a lead proposes a worker roster (the staffing gate)
+    )
+    ITEMS_PROPOSED = (
+        "items_proposed"  # a lead proposes work items (the decomposition gate);
+        # unlike propose_plan this is mode-independent — approval creates the items
+    )
+    TOOL_STARTED = "tool_started"
+    TOOL_FINISHED = "tool_finished"
+    ITERATION_END = "iteration_end"
+    TURN_END = "turn_end"
+    ERROR = "error"
+    INTERRUPTED = "interrupted"
+    COMPACTING = "compacting"  # compaction started — surfaces show a transient signal
+    COMPACTED = "compacted"  # outbound history was compacted (summary or trim)
+
+
+@dataclass
+class Event:
+    type: EventType
+    data: dict[str, Any] = field(default_factory=dict)