Fix compose file probe: use FileStation.List/getinfo instead of FileStation.Info/get

SYNO.FileStation.Info/get is a system-info API and returns success
regardless of whether a path exists, so the probe always returned the
first candidate (docker-compose.yml) even when only compose.yaml
was present. SYNO.FileStation.List/getinfo returns {"files": [...]}
with an empty list for non-existent paths, enabling correct detection.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/mcp_synology_container/modules/compose.py

@@ -329,11 +329,12 @@ async def _find_compose_path(
     for filename in _COMPOSE_FILENAMES:
         path = f"{base}/{filename}"
         try:
-            await client.request(
+            data = await client.request(
-                "SYNO.FileStation.Info",
+                "SYNO.FileStation.List",
-                "get",
+                "getinfo",
                 params={"path": path, "additional": "[]"},
             )
+            if data.get("files"):
                 logger.debug("Found compose file: %s", path)
                 return path
         except Exception: