Implement ViewIt Plugin System Documentation and Update Project Notes

- Added comprehensive documentation for the ViewIt Plugin System, detailing the plugin loading process, required methods, optional features, and community extension workflow.
- Updated project notes to reflect the current structure, build process, search logic, and known issues.
- Introduced new build scripts for installing the add-on and creating ZIP packages.
- Added test scripts for TMDB API integration, including argument parsing and logging functionality.
- Enhanced existing plugins with improved search logic and error handling.

addon/plugin_interface.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+"""Gemeinsame Schnittstelle fuer Kodi-Plugins."""
+
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import List, Optional, Set
+
+
+class BasisPlugin(ABC):
+    """Abstrakte Basisklasse fuer alle Integrationen."""
+
+    name: str
+
+    @abstractmethod
+    async def search_titles(self, query: str) -> List[str]:
+        """Liefert eine Liste aller Treffer fuer die Suche."""
+
+    @abstractmethod
+    def seasons_for(self, title: str) -> List[str]:
+        """Liefert alle Staffeln zu einem Titel."""
+
+    @abstractmethod
+    def episodes_for(self, title: str, season: str) -> List[str]:
+        """Liefert alle Folgen zu einer Staffel."""
+
+    def stream_link_for(self, title: str, season: str, episode: str) -> Optional[str]:
+        """Optional: Liefert den Stream-Link fuer eine konkrete Folge."""
+        return None
+
+    def resolve_stream_link(self, link: str) -> Optional[str]:
+        """Optional: Folgt einem Stream-Link und liefert die finale URL."""
+        return None
+
+    def genres(self) -> List[str]:
+        """Optional: Liefert eine Liste an Genres (falls verfügbar)."""
+        return []
+
+    def titles_for_genre(self, genre: str) -> List[str]:
+        """Optional: Liefert alle Serientitel zu einem Genre."""
+        return []
+
+    def capabilities(self) -> Set[str]:
+        """Optional: Liefert eine Menge an Features/Capabilities dieses Plugins.
+
+        Beispiele:
+        - `popular_series`: Plugin kann eine Liste beliebter Serien liefern.
+        """
+
+        return set()
+
+    def popular_series(self) -> List[str]:
+        """Optional: Liefert eine Liste beliebter Serien (als Titel-Strings)."""
+
+        return []