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/core/config_manager.py

@@ -186,6 +186,20 @@ class ConfigManager:
             return len(self.config.environments) > 0
     # [/DEF:has_environments:Function]
 
+    # [DEF:get_environment:Function]
+    # @PURPOSE: Returns a single environment by ID.
+    # @PRE: self.config is set and isinstance(env_id, str) and len(env_id) > 0.
+    # @POST: Returns Environment object if found, None otherwise.
+    # @PARAM: env_id (str) - The ID of the environment to retrieve.
+    # @RETURN: Optional[Environment] - The environment with the given ID, or None.
+    def get_environment(self, env_id: str) -> Optional[Environment]:
+        with belief_scope("get_environment"):
+            for env in self.config.environments:
+                if env.id == env_id:
+                    return env
+            return None
+    # [/DEF:get_environment:Function]
+
     # [DEF:add_environment:Function]
     # @PURPOSE: Adds a new environment to the configuration.
     # @PRE: isinstance(env, Environment)

backend/src/core/superset_client.py

@@ -9,7 +9,7 @@
 
 # [SECTION: IMPORTS]
 from typing import List, Dict, Optional, Tuple
-from backend.src.core.logger import belief_scope
+from .logger import belief_scope
 from superset_tool.client import SupersetClient as BaseSupersetClient
 from superset_tool.models import SupersetConfig
 # [/SECTION]
@@ -17,6 +17,14 @@ from superset_tool.models import SupersetConfig
 # [DEF:SupersetClient:Class]
 # @PURPOSE: Extended SupersetClient for migration-specific operations.
 class SupersetClient(BaseSupersetClient):
+    # [DEF:authenticate:Function]
+    # @PURPOSE: Authenticates the client using the configured credentials.
+    # @PRE: self.network must be initialized with valid auth configuration.
+    # @POST: Client is authenticated and tokens are stored.
+    # @RETURN: Dict[str, str] - Authentication tokens.
+    def authenticate(self):
+        with belief_scope("SupersetClient.authenticate"):
+            return self.network.authenticate()
     
     # [DEF:get_databases_summary:Function]
     # @PURPOSE: Fetch a summary of databases including uuid, name, and engine.