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

tests/test_session_persona.py

@@ -0,0 +1,74 @@
+"""Phase 1 gate — a session is born from exactly one persona; pin + rename persist.
+
+The persona binding rides on the existing ``SessionRecord.agent`` column (immutable in
+practice — ``get_engine`` always rebuilds from it). Pin = ``pinned`` flag; rename = ``title``.
+"""
+
+from __future__ import annotations
+
+from coworker.conversations import ConversationStore
+from coworker.sessions import SessionRecord
+
+
+def _store(tmp_path) -> ConversationStore:
+    return ConversationStore(tmp_path)
+
+
+def test_session_records_its_persona(tmp_path):
+    store = _store(tmp_path)
+    store.save(
+        SessionRecord(
+            session_id="s1",
+            workspace=str(tmp_path),
+            model="gpt-5.5",
+            mode="interactive",
+            agent="ops",
+        )
+    )
+    loaded = store.load("s1")
+    assert loaded is not None and loaded.agent == "ops"
+
+
+def test_persona_binding_is_stable_across_reload(tmp_path):
+    store = _store(tmp_path)
+    store.save(
+        SessionRecord(
+            session_id="s2",
+            workspace=str(tmp_path),
+            model="gpt-5.5",
+            mode="interactive",
+            agent="code",
+        )
+    )
+    # A fresh store instance over the same dir still sees the original persona.
+    assert _store(tmp_path).load("s2").agent == "code"
+
+
+def test_pin_persists(tmp_path):
+    store = _store(tmp_path)
+    store.save(
+        SessionRecord(
+            session_id="s3",
+            workspace=str(tmp_path),
+            model="gpt-5.5",
+            mode="interactive",
+            agent="ops",
+        )
+    )
+    assert store.set_flags("s3", pinned=True)
+    assert store.load("s3").pinned is True
+
+
+def test_rename_persists(tmp_path):
+    store = _store(tmp_path)
+    store.save(
+        SessionRecord(
+            session_id="s4",
+            workspace=str(tmp_path),
+            model="gpt-5.5",
+            mode="interactive",
+            agent="ops",
+        )
+    )
+    assert store.rename("s4", "Release Captain")
+    assert store.load("s4").title == "Release Captain"