fix: unblock event loop for analyze_repo, detach git subprocess stdin on Windows

- Run analyze_repo via asyncio.to_thread under an asyncio.Lock: keeps
  tree-sitter usage serialized without blocking the MCP stdio pump
  (aligns with the to_thread pattern used by all other sync handlers)
- Add stdin=DEVNULL to GitIgnoreFilter's git calls so children never
  inherit the MCP JSON-RPC stdin pipe, which hangs on Windows
  ProactorEventLoop

Author: huanceng

codewiki/mcp/server.py

@@ -372,6 +372,8 @@ async def list_tools() -> list[Tool]:
     return _fine_grained_tools() + _legacy_tools()
 
 
+_analyze_lock = asyncio.Lock()
+
 @server.call_tool()
 async def call_tool(name: str, arguments: dict[str, Any]) -> list[TextContent]:
     """Route tool calls to the appropriate handler."""
@@ -382,10 +384,11 @@ async def call_tool(name: str, arguments: dict[str, Any]) -> list[TextContent]:
         if name == "analyze_repo":
             from codewiki.mcp.tools.analysis import handle_analyze_repo
 
-            # NOTE: Tree-sitter C extensions are not thread-safe, so this
-            # must run on the main thread (blocking the event loop is
-            # acceptable for this one-time heavy operation).
-            return [_text(handle_analyze_repo(arguments, _store))]
+            # NOTE: Tree-sitter C extensions are not thread-safe, so we use
+            # a lock to ensure only one analyze_repo runs at a time, but
+            # offload to a thread to avoid blocking the stdio pump.
+            async with _analyze_lock:
+                return [_text(await asyncio.to_thread(handle_analyze_repo, arguments, _store))]
 
         elif name == "read_code_components":
             from codewiki.mcp.tools.code_reader import handle_read_code_components

codewiki/src/be/dependency_analyzer/analysis/repo_analyzer.py

@@ -54,6 +54,7 @@ def _load_git_ignored_paths(self) -> bool:
                 capture_output=True,
                 text=True,
                 timeout=10,
+                stdin=subprocess.DEVNULL,
             )
             if root_result.returncode != 0:
                 logger.debug(
@@ -82,6 +83,7 @@ def _load_git_ignored_paths(self) -> bool:
                 check=True,
                 capture_output=True,
                 timeout=30,
+                stdin=subprocess.DEVNULL,
             )
         except (OSError, ValueError, subprocess.SubprocessError) as exc:
             logger.warning(