fix: auto-scan cloud libraries on boot + allow CORS for media playback

- Add BootCloudLibraries() to auto-scan all cloud libraries on startup
- Delay 3s to avoid conflict with system init, scan without auto-scrape
- Enable CORS for /api/cloud/play/* and /api/img to support 3rd-party players
- Fixes issue where each user triggers separate cloud library scans
- Fixes issue where Infuse/Emby apps cannot play cloud resources

internal/service/discover.go

@@ -159,7 +159,7 @@ func (d *DiscoverService) Fetch(ctx context.Context, path string) ([]Match, erro
 			date = r.FirstAirDate
 		}
 		if len(date) >= 4 {
-			fmt.Sscanf(date[:4], "%d", &m.Year)
+			_, _ = fmt.Sscanf(date[:4], "%d", &m.Year)
 		}
 		out = append(out, m)
 	}