fix(backend): standardize superset client init and auth

- Update plugins (debug, mapper, search) to explicitly map environment config to SupersetConfig
- Add authenticate method to SupersetClient for explicit session management
- Add get_environment method to ConfigManager
- Fix navbar dropdown hover stability in frontend with invisible bridge

backend/src/plugins/mapper.py

@@ -137,13 +137,25 @@ class MapperPlugin(PluginBase):
 
             # Get config and initialize client
             from ..dependencies import get_config_manager
+            from superset_tool.models import SupersetConfig
             config_manager = get_config_manager()
             env_config = config_manager.get_environment(env_name)
             if not env_config:
                 logger.error(f"[MapperPlugin.execute][State] Environment '{env_name}' not found.")
                 raise ValueError(f"Environment '{env_name}' not found in configuration.")
 
-            client = SupersetClient(env_config)
+            # Map Environment model to SupersetConfig
+            superset_config = SupersetConfig(
+                env=env_config.name,
+                base_url=env_config.url,
+                auth={
+                    "provider": "db",  # Defaulting to db provider
+                    "username": env_config.username,
+                    "password": env_config.password,
+                    "refresh": "false"
+                }
+            )
+            client = SupersetClient(superset_config)
             client.authenticate()
 
             postgres_config = None