Fix: Always reload channels on preview/add actions to prevent stale data

Changes:
- Modified preview_changes_action to always reload channels before previewing
- Modified add_streams_to_channels_action to always reload channels before adding streams
- Removed file existence check that prevented reload when data was stale
- This ensures deleted channels (like ES DAZN 09/10) won't cause warnings

The processed data file is now refreshed on every preview/add operation,
ensuring users always work with current channel data from the Dispatcharr API.

Stream-Mapparr/plugin.py

@@ -2421,9 +2421,8 @@ class Plugin:
 
     def preview_changes_action(self, settings, logger, context=None):
         """Preview which streams will be added to channels without making changes."""
-        # Auto-load channels if not already loaded
-        if not os.path.exists(self.processed_data_file):
-            logger.info("[Stream-Mapparr] No processed data found, loading channels automatically...")
+        # Always reload channels to ensure fresh data
+        logger.info("[Stream-Mapparr] Loading fresh channel and stream data...")
         self._send_progress_update("preview_changes", 'running', 0, 'Loading channels and streams...', context)
         load_result = self.load_process_channels_action(settings, logger, context)
         if load_result.get('status') != 'success':
@@ -2596,9 +2595,8 @@ class Plugin:
 
     def add_streams_to_channels_action(self, settings, logger, is_scheduled=False, context=None):
         """Add matching streams to channels and replace existing stream assignments."""
-        # Auto-load channels if not already loaded
-        if not os.path.exists(self.processed_data_file):
-            logger.info("[Stream-Mapparr] No processed data found, loading channels automatically...")
+        # Always reload channels to ensure fresh data
+        logger.info("[Stream-Mapparr] Loading fresh channel and stream data...")
         self._send_progress_update("add_streams_to_channels", 'running', 0, 'Loading channels and streams...', context)
         load_result = self.load_process_channels_action(settings, logger, context)
         if load_result.get('status') != 'success':