Feature/delta team/epic r04 (#7)

## Summary

epic r04 - begin refactor

## Change Type

- [x] Cowork feature
- [ ] Bug fix
- [ ] Core AI contribution
- [ ] Test / hardening
- [ ] Performance
- [ ] Documentation

## Related Work

Cowork Task:

Core Repo: http://34.143.229.138/gitea-admin/fsg-ai-core-assets

Core AI Issue:

Core Task:

Related PR:

## Scope

What is intentionally included?

What is intentionally NOT included?

## Validation

- [ ] Unit tests
- [ ] Integration tests
- [ ] Manual verification
- [ ] Regression check

Commands / evidence:

## Security Impact

Permission / credential / network / customer data impact:

## Compatibility

- [ ] No breaking change
- [ ] Breaking change documented

## Reviewer Notes

Anything Cowork reviewers should pay attention to.

---------

Co-authored-by: Anh Tran Nguyen Minh <anhtnm1@fpt.com>
Co-authored-by: Huong Le Thi Thien <huongltt35@fpt.com>
Co-authored-by: Nam Pham Dinh Thanh <nampdt@fpt.com>
Co-authored-by: Vu Dam Tuan <vudt15@fpt.com>
Co-authored-by: Hiep Ha Van <hiephv3@fpt.com>
Co-authored-by: Lam Hoang Van <lamhv7@fpt.com>
Reviewed-on: #7
Co-authored-by: Duy Le Huu <duylh19@fpt.com>

infrastructure/mcp/mcp_source_manager.py

@@ -0,0 +1,119 @@
+"""McpToolSourceManager - the MCP server connection lifecycle, extracted out
+of ``state.py::AppContext`` (R05-T05).
+
+Today ``AppContext.build_mcp_tools`` inlines all of this: a ``_mcp_connections``
+dict, a ``_conn_lock`` guarding check-then-create against concurrent turns (a
+Cowork tab, a Co4E flow and a Scheduled Task can all call it at once), and a
+"start it, cache it, skip it on failure" loop repeated for both the
+admin-configured servers AND the built-in MS365 server
+(``_ms365_builtin_connection``). None of that logic touches Qt; it was only
+ever inline because ``AppContext`` is where the config lived.
+
+This class owns the SAME cache/lock/start-or-skip behavior as a standalone,
+directly testable object — ``AppContext`` becomes a thin caller (one instance
+per app, same as it holds one ``RoutingApplicationService``).
+
+Pure Python: no Qt. It DOES touch the network/filesystem via
+``core.mcp_client.McpServerConnection`` (a subprocess + asyncio loop), which is
+exactly what makes it infrastructure rather than domain.
+"""
+from __future__ import annotations
+
+import threading
+from typing import Dict, List, Optional
+
+from cowork_local.core.mcp_client import McpServerConnection
+
+
+class McpToolSourceManager:
+    """Caches and supervises one :class:`McpServerConnection` per server name.
+
+    ``connection_factory`` defaults to ``McpServerConnection`` itself; tests
+    substitute a fake so no real subprocess is spawned (see
+    ``tests/unit/test_mcp_source_manager.py``).
+    """
+
+    def __init__(self, connection_factory=McpServerConnection) -> None:
+        """``connection_factory`` tiêm được để test không phải chạy tiến trình con thật.
+
+        Có khoá riêng vì nhiều lượt chat song song cùng gọi tới đây: kiểm-rồi-tạo mà
+        không khoá sẽ dựng hai kết nối cho cùng một máy chủ.
+        """
+        self._connections: Dict[str, McpServerConnection] = {}
+        self._lock = threading.Lock()
+        self._connection_factory = connection_factory
+
+    def ensure(self, name: str, command: str, args: Optional[List[str]] = None,
+               env: Optional[Dict[str, str]] = None) -> Optional[McpServerConnection]:
+        """Return a live connection for ``name``, starting one if there is
+        none cached or the cached one's subprocess has died.
+
+        Serialized under one lock so two turns racing to build their tool
+        list at the same moment share one subprocess per server instead of
+        each spawning their own (the bug this replaces:
+        ``AppContext._conn_lock``'s original docstring). Returns ``None`` -
+        never raises - when the server fails to start, matching the existing
+        "one broken server must not block the turn" behavior.
+        """
+        with self._lock:
+            existing = self._connections.get(name)
+            if existing is not None and existing.is_alive():
+                return existing
+            if existing is not None:
+                self._connections.pop(name, None)
+            connection = self._connection_factory(name, command, args or [], env)
+            try:
+                connection.start()
+            except Exception:  # noqa: BLE001 - one broken server must not block the turn
+                return None
+            self._connections[name] = connection
+            return connection
+
+    def get(self, name: str) -> Optional[McpServerConnection]:
+        """The cached connection for ``name``, without starting one."""
+        return self._connections.get(name)
+
+    def is_alive(self, name: str) -> bool:
+        """Kết nối tới một MCP server còn sống không."""
+        connection = self._connections.get(name)
+        return connection is not None and connection.is_alive()
+
+    def restart(self, name: str, command: str, args: Optional[List[str]] = None,
+                env: Optional[Dict[str, str]] = None) -> Optional[McpServerConnection]:
+        """Force a fresh connection for ``name`` even if the cached one still
+        looks alive - for a server the caller knows is misbehaving."""
+        with self._lock:
+            self._connections.pop(name, None)
+        return self.ensure(name, command, args, env)
+
+    def stop(self, name: str) -> None:
+        """Stop and forget one connection - used when a server becomes
+        unavailable by configuration (e.g. MS365 signed out) rather than by
+        crashing."""
+        with self._lock:
+            connection = self._connections.pop(name, None)
+        if connection is not None:
+            try:
+                connection.stop()
+            except Exception:  # noqa: BLE001 - shutdown must never raise into the caller
+                pass
+
+    def active(self) -> List[McpServerConnection]:
+        """Every currently cached connection - what
+        ``core/mcp_client.py::build_mcp_tools`` merges tool specs from."""
+        return list(self._connections.values())
+
+    def stop_all(self) -> None:
+        """Terminate every connection's subprocess - called on app shutdown
+        so none of them linger as orphan processes."""
+        with self._lock:
+            connections = list(self._connections.values())
+            self._connections.clear()
+        for connection in connections:
+            try:
+                connection.stop()
+            except Exception:  # noqa: BLE001
+                pass
+
+
+__all__ = ["McpToolSourceManager"]