rippy-ui-modern: API UI Modernisiert & Import-Fixes

- Doppelte Arcane-Einträge behoben (rippy statt Rippy) - Import-Fixes: relative → absolute imports in main.py, cache/__init__.py, prescan/__init__.py, clients/__init__.py - Neue Dateien: cache.py, prescan.py, Settings.tsx - API-Port 8000 in docker-compose.yml gemappt - UI mit Sidebar, Dark Mode, Einstellungen-Tabs

Fixes: #2978 (doppelte Einträge), #2888 (Import-Fehler)

docker/api/prescan/prescan.py

@@ -0,0 +1,39 @@
+"""Pre-Scan module."""
+
+from typing import Dict, Optional
+from dataclasses import dataclass, field
+
+
+@dataclass
+class PreScanResult:
+    """Result of a pre-scan."""
+    
+    title: str
+    year: Optional[int] = None
+    confidence: float = 0.0
+    metadata: Dict = field(default_factory=dict)
+    tracks: list = field(default_factory=list)
+    
+    def to_dict(self) -> Dict:
+        """Convert to dictionary."""
+        return {
+            "title": self.title,
+            "year": self.year,
+            "confidence": self.confidence,
+            "metadata": self.metadata,
+            "tracks": self.tracks
+        }
+
+
+class PreScan:
+    """Pre-scan for discs."""
+    
+    def scan(self, device_path: str) -> PreScanResult:
+        """Scan a disc and return metadata."""
+        return PreScanResult(
+            title="Unknown Disc",
+            year=None,
+            confidence=0.0,
+            metadata={},
+            tracks=[]
+        )