fix: catch SystemError from os.kill on Windows

On Windows, os.kill(pid, 0) raises SystemError when the target process
has exited but its handle state is in transition (WinError 87). This
corrupts CPython C exception state, causing subsequent built-in calls
like time.monotonic() to also raise SystemError.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: georgeh0

src/cocoindex_code/client.py

@@ -227,8 +227,11 @@ def _pid_alive(pid: int) -> bool:
         return False
     except PermissionError:
         return True  # process exists but we can't signal it
-    except OSError:
-        return False  # assume dead on unexpected OS errors (e.g. Windows edge cases)
+    except (OSError, SystemError):
+        # On Windows, os.kill(pid, 0) can raise SystemError or unexpected OSError
+        # variants (e.g. WinError 87 "The parameter is incorrect") for PIDs that
+        # have exited but whose handles haven't been fully released.
+        return False
 
 
 def stop_daemon() -> None: