Optimize startup: skip series loading on every SeriesApp init

- SeriesApp now passes skip_load=True to SerieList
- Prevents redundant data file loading on every startup
- Series loaded once during setup via sync_series_from_data_files()
- Removed obsolete _init_list_sync() and _init_list() methods
- Updated documentation in ARCHITECTURE.md and README.md

src/core/SeriesApp.py

@@ -164,11 +164,12 @@ class SeriesApp:
         self.serie_scanner = SerieScanner(
             directory_to_search, self.loader
         )
-        self.list = SerieList(self.directory_to_search)
+        # Skip automatic loading from data files - series will be loaded
+        # from database by the service layer during application setup
+        self.list = SerieList(self.directory_to_search, skip_load=True)
         self.series_list: List[Any] = []
-        # Synchronous init used during constructor to avoid awaiting
-        # in __init__
-        self._init_list_sync()
+        # Initialize empty list - series loaded later via load_series_from_list()
+        # No need to call _init_list_sync() anymore
         
         # Initialize NFO service if TMDB API key is configured
         self.nfo_service: Optional[NFOService] = None
@@ -242,26 +243,6 @@ class SeriesApp:
             len(self.series_list)
         )
 
-    def _init_list_sync(self) -> None:
-        """Synchronous initialization helper for constructor."""
-        self.series_list = self.list.GetMissingEpisode()
-        logger.debug(
-            "Loaded %d series with missing episodes",
-            len(self.series_list)
-        )
-
-    async def _init_list(self) -> None:
-        """Initialize the series list with missing episodes (async)."""
-        loop = asyncio.get_running_loop()
-        self.series_list = await loop.run_in_executor(
-            self.executor,
-            self.list.GetMissingEpisode
-        )
-        logger.debug(
-            "Loaded %d series with missing episodes",
-            len(self.series_list)
-        )
-
     async def search(self, words: str) -> List[Dict[str, Any]]:
         """
         Search for anime series (async).