fix(13-02): resolve phantom playlist tracks using M3U8 paths after scan

- Add ScanHooks callback struct to library package (follows RemovalHooks pattern)
- Move phantom resolution from library to playlist service via hook
- New ResolvePhantomTracksAfterScan reads M3U8 files and resolves paths
  against current audio_files using multi-root resolution
- Handles pre-existing phantoms (match by M3U8 position) and new ones
  (match by phantom_file_path)
- Delete old resolvePhantomTracks method that required phantom_file_path
- Wire ScanHooks in app.go OnStartup

frontend/wailsjs/go/models.ts

@@ -134,6 +134,18 @@ export namespace library {
 	
 	    }
 	}
+	export class ScanHooks {
+	
+	
+	    static createFrom(source: any = {}) {
+	        return new ScanHooks(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	
+	    }
+	}
 	export class ScanWarning {
 	    filePath: string;
 	    phase: string;