Fix health check: DB file is always local, not remote

In REMOTE_MODE the SQLite database lives inside the MCP container,
not on the remote HAProxy host. Check db_file with os.path.exists
instead of remote_file_exists.

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

haproxy_mcp/tools/health.py

@@ -90,7 +90,11 @@ def register_health_tools(mcp):
         files_ok = True
         file_status: dict[str, str] = {}
         for name, path in [("map_file", MAP_FILE), ("db_file", DB_FILE)]:
-            exists = remote_file_exists(path) if REMOTE_MODE else __import__('os').path.exists(path)
+            # DB file is always local (SQLite runs in MCP container), map_file may be remote
+            if name == "db_file" or not REMOTE_MODE:
+                exists = __import__('os').path.exists(path)
+            else:
+                exists = remote_file_exists(path)
             if exists:
                 file_status[name] = "ok"
             else: