style(backend): biome format — organize imports + spacing (live-speaker/redis-bridge/voice.service)

services/backend/src/modules/voice/live-speaker.ts

@@ -80,4 +80,4 @@ export function getSpeakingSpeakers(): LiveSpeaker[] {
 /** Drop all tracked speakers (used on backend restart). */
 export function resetLiveSpeakers(): void {
   speakers.clear();
-}
+}