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/debug.py

@@ -145,7 +145,19 @@ class DebugPlugin(PluginBase):
             if not env_config:
                 raise ValueError(f"Environment '{name}' not found.")
             
-            client = SupersetClient(env_config)
+            # Map Environment model to SupersetConfig
+            from superset_tool.models import 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()
             count, dbs = client.get_databases()
             results[name] = {
@@ -176,7 +188,19 @@ class DebugPlugin(PluginBase):
         if not env_config:
             raise ValueError(f"Environment '{env_name}' not found.")
             
-        client = SupersetClient(env_config)
+        # Map Environment model to SupersetConfig
+        from superset_tool.models import 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()
         
         dataset_response = client.get_dataset(dataset_id)