Fix: Voice claim system - radio stops when soundboard plays

Plugins now claim voice per guild via claimVoice(). When soundboard
plays a sound, radio's cleanup runs automatically (kills ffmpeg,
broadcasts SSE stop event). Fixes stale "now playing" UI on tab switch.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/core/plugin.ts

@@ -39,3 +39,25 @@ export function registerPlugin(plugin: Plugin): void {
 export function getPlugins(): Plugin[] {
   return [...loadedPlugins];
 }
+
+// ── Voice claim system ──
+// Only one plugin can use voice per guild. When a new plugin claims voice,
+// the previous claimant's cleanup callback is invoked automatically.
+type VoiceClaimCleanup = () => void;
+const voiceClaims = new Map<string, { plugin: string; cleanup: VoiceClaimCleanup }>();
+
+export function claimVoice(guildId: string, pluginName: string, cleanup: VoiceClaimCleanup): void {
+  const existing = voiceClaims.get(guildId);
+  if (existing && existing.plugin !== pluginName) {
+    console.log(`[Voice] ${pluginName} claims guild ${guildId}, releasing ${existing.plugin}`);
+    existing.cleanup();
+  }
+  voiceClaims.set(guildId, { plugin: pluginName, cleanup });
+}
+
+export function releaseVoice(guildId: string, pluginName: string): void {
+  const claim = voiceClaims.get(guildId);
+  if (claim?.plugin === pluginName) {
+    voiceClaims.delete(guildId);
+  }
+}

server/src/plugins/radio/index.ts

@@ -7,6 +7,7 @@ import {
 import type { VoiceBasedChannel } from 'discord.js';
 import { ChannelType } from 'discord.js';
 import type { Plugin, PluginContext } from '../../core/plugin.js';
+import { claimVoice, releaseVoice } from '../../core/plugin.js';
 import { sseBroadcast } from '../../core/sse.js';
 import { getState, setState } from '../../core/persistence.js';
 import {
@@ -68,6 +69,7 @@ function stopStream(guildId: string): void {
   try { state.player.stop(true); } catch {}
   try { getVoiceConnection(guildId)?.destroy(); } catch {}
   guildRadioState.delete(guildId);
+  releaseVoice(guildId, 'radio');
   broadcastState(guildId);
   console.log(`[Radio] Stopped stream in guild ${guildId}`);
 }
@@ -148,6 +150,9 @@ async function startStream(
     stopStream(guildId);
   });
 
+  // Claim voice for this guild (stops other plugins like soundboard)
+  claimVoice(guildId, 'radio', () => stopStream(guildId));
+
   // State tracken
   const channelName = 'name' in channel ? (channel as any).name : voiceChannelId;
   guildRadioState.set(guildId, {

server/src/plugins/soundboard/index.ts

@@ -16,6 +16,7 @@ import sodium from 'libsodium-wrappers';
 import nacl from 'tweetnacl';
 import { ChannelType, Events, type VoiceState, type Message } from 'discord.js';
 import type { Plugin, PluginContext } from '../../core/plugin.js';
+import { claimVoice } from '../../core/plugin.js';
 import { sseBroadcast } from '../../core/sse.js';
 
 // ── Config (env) ──
@@ -332,6 +333,8 @@ let _pluginCtx: PluginContext | null = null;
 
 async function playFilePath(guildId: string, channelId: string, filePath: string, volume?: number, relativeKey?: string): Promise<void> {
   console.log(`${SB} playFilePath: guild=${guildId} channel=${channelId} file=${path.basename(filePath)} vol=${volume ?? 'default'}`);
+  // Claim voice for this guild (stops radio if playing)
+  claimVoice(guildId, 'soundboard', () => { /* soundboard cleanup handled by lifecycle */ });
   const ctx = _pluginCtx!;
   const guild = ctx.client.guilds.cache.get(guildId);
   if (!guild) { console.error(`${SB} Guild ${guildId} not found in cache (cached: ${ctx.client.guilds.cache.map(g => g.id).join(', ')})`); throw new Error('Guild nicht gefunden'); }