Convert track duration to milliseconds in search results

Updated the duration field in TrackResult to store duration in milliseconds instead of seconds, matching Spotify's expected format. This ensures consistency when integrating with services that use millisecond-based durations.

core/soulseek_client.py

@@ -18,7 +18,7 @@ class SearchResult:
     filename: str
     size: int
     bitrate: Optional[int]
-    duration: Optional[int]
+    duration: Optional[int]  # Duration in milliseconds (converted from slskd's seconds)
     quality: str
     free_upload_slots: int
     upload_speed: int
@@ -429,12 +429,16 @@ class SoulseekClient:
                 quality = file_ext if file_ext in ['flac', 'mp3', 'ogg', 'aac', 'wma'] else 'unknown'
                 
                 # Create TrackResult
+                # Convert duration from seconds to milliseconds (slskd returns seconds, Spotify uses ms)
+                raw_duration = file_data.get('length')
+                duration_ms = raw_duration * 1000 if raw_duration else None
+
                 track = TrackResult(
                     username=username,
                     filename=filename,
                     size=size,
                     bitrate=file_data.get('bitRate'),
-                    duration=file_data.get('length'),
+                    duration=duration_ms,
                     quality=quality,
                     free_upload_slots=response_data.get('freeUploadSlots', 0),
                     upload_speed=response_data.get('uploadSpeed', 0),