Task 1.4: Update provider classes to use key as primary identifier

- Enhanced download() method docstring in aniworld_provider.py
- Enhanced Download() method docstring in enhanced_provider.py
- Clarified that 'key' is the series unique identifier from provider
- Clarified that 'serie_folder'/'serieFolder' is filesystem folder name (metadata only)
- Added comprehensive Args, Returns, and Raises sections to docstrings
- Fixed PEP 8 line length issue in logging statement
- Verified existing code already uses 'key' for identification and logging
- All 34 provider-related tests pass successfully
- No functional changes required, documentation improvements only

src/core/SerieScanner.py

@@ -13,10 +13,7 @@ import uuid
 from typing import Callable, Iterable, Iterator, Optional
 
 from src.core.entities.series import Serie
-from src.core.exceptions.Exceptions import (
-    MatchNotFoundError,
-    NoKeyFoundException,
-)
+from src.core.exceptions.Exceptions import MatchNotFoundError, NoKeyFoundException
 from src.core.interfaces.callbacks import (
     CallbackManager,
     CompletionContext,

src/core/providers/aniworld_provider.py

@@ -208,8 +208,26 @@ class AniworldLoader(Loader):
         language: str = "German Dub",
         progress_callback=None
     ) -> bool:
-        """Download episode to specified directory."""
-        logging.info(f"Starting download for S{season:02}E{episode:03} ({key}) in {language}")
+        """Download episode to specified directory.
+        
+        Args:
+            base_directory: Base download directory path
+            serie_folder: Filesystem folder name (metadata only, used for
+                file path construction)
+            season: Season number
+            episode: Episode number
+            key: Series unique identifier from provider (used for
+                identification and API calls)
+            language: Audio language preference (default: German Dub)
+            progress_callback: Optional callback for download progress
+            
+        Returns:
+            bool: True if download succeeded, False otherwise
+        """
+        logging.info(
+            f"Starting download for S{season:02}E{episode:03} "
+            f"({key}) in {language}"
+        )
         sanitized_anime_title = ''.join(
             char for char in self.get_title(key)
             if char not in self.INVALID_PATH_CHARS

src/core/providers/enhanced_provider.py

@@ -349,7 +349,27 @@ class EnhancedAniWorldLoader(Loader):
         language: str = "German Dub",
         progress_callback: Optional[Callable] = None,
     ) -> bool:
-        """Download episode with comprehensive error handling."""
+        """Download episode with comprehensive error handling.
+        
+        Args:
+            baseDirectory: Base download directory path
+            serieFolder: Filesystem folder name (metadata only, used for
+                file path construction)
+            season: Season number (0 for movies)
+            episode: Episode number
+            key: Series unique identifier from provider (used for
+                identification and API calls)
+            language: Audio language preference (default: German Dub)
+            progress_callback: Optional callback for download progress
+                updates
+            
+        Returns:
+            bool: True if download succeeded, False otherwise
+            
+        Raises:
+            DownloadError: If download fails after all retry attempts
+            ValueError: If required parameters are missing or invalid
+        """
         self.download_stats["total_downloads"] += 1
 
         try: