feat(backend): lyra voice picker for legend (mvp)

- profile.ts: Whitelist (null | iFSsEDGbm0FiEd2IVH4w | Gt7OshJCH7MuzX96wFHi) + setLyraVoiceId()
- profile/me/lyra-voice.patch.ts: neuer Endpoint, Legend-Gate (403 legend_only),
  Validation gegen Whitelist (400 invalid_voice_id). DB-Wert bleibt bei Plan-Downgrade.
- coach/speak.post.ts: ElevenLabs-Voice-Prioritätskette nimmt userLyraVoiceId
  zuerst (nur wenn plan === legend), sonst voiceCfg / config / env / FALLBACK.
- auth/me.get.ts: lyraVoiceId in der Profile-Response damit Frontend hydriert.

Schema-Feld lyraVoiceId existiert bereits aus migration
20260507_profile_demographics_and_trial — keine neue Migration nötig.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/server/api/auth/me.get.ts

@@ -22,6 +22,7 @@ export default defineEventHandler(async (event) => {
     plan,
     foundingMember: dbProfile?.foundingMember ?? false,
     streak: dbProfile?.streak ?? 0,
+    lyraVoiceId: dbProfile?.lyraVoiceId ?? null,
     created_at: dbProfile?.createdAt?.toISOString() ?? user.created_at,
     // Für useUserPlan im Frontend — Key-Subset der PlanLimits
     planLimits: {

backend/server/api/coach/speak.post.ts

@@ -46,9 +46,11 @@ export default defineEventHandler(async (event) => {
   const db = usePrisma();
   const profile = await db.profile.findUnique({
     where: { id: user.id },
-    select: { plan: true },
+    select: { plan: true, lyraVoiceId: true },
   });
   const plan = (profile?.plan ?? "free").toLowerCase();
+  // lyraVoiceId nur für legend wirksam — plan-check im speakElevenLabs
+  const userLyraVoiceId = plan === "legend" ? (profile?.lyraVoiceId ?? null) : null;
 
   const limits = getPlanLimits(plan);
   const voiceCfg = limits.voice;
@@ -78,7 +80,7 @@ export default defineEventHandler(async (event) => {
     case "cartesia":
       return await speakCartesia(event, trimmed, config, voiceCfg, user.id, plan);
     case "elevenlabs":
-      return await speakElevenLabs(event, trimmed, mode, config, voiceCfg, user.id, plan);
+      return await speakElevenLabs(event, trimmed, mode, config, voiceCfg, user.id, plan, userLyraVoiceId);
     default: {
       // Unknown provider in config — fallback to Google with warning
       console.warn("[speak] unknown provider in plan-features:", voiceCfg.provider, "→ falling back to google");
@@ -211,6 +213,7 @@ async function speakElevenLabs(
   voiceCfg: VoiceConfig,
   userId: string,
   plan: string,
+  userLyraVoiceId: string | null = null,
 ) {
   const key =
     (config.elevenlabsApiKey as string) || process.env.ELEVENLABS_API_KEY || "";
@@ -219,7 +222,9 @@ async function speakElevenLabs(
   }
 
   const ELEVENLABS_FALLBACK_VOICE = "kdmDKE6EkgrWrrykO9Qt"; // Alexandra
+  // User-Voice hat höchste Priorität (bereits plan-gefiltert vom Caller)
   const voiceId =
+    userLyraVoiceId ||
     voiceCfg.voiceId ||
     (config.elevenlabsVoiceId as string) ||
     process.env.ELEVENLABS_VOICE_ID ||

backend/server/api/profile/me/lyra-voice.patch.ts

@@ -0,0 +1,43 @@
+import { setLyraVoiceId, isAllowedLyraVoiceId } from "../../../db/profile";
+
+/**
+ * PATCH /api/profile/me/lyra-voice
+ *
+ * Legend-only. Setzt die ElevenLabs-Voice-ID für Lyra-TTS.
+ *
+ * Body: { lyraVoiceId: string | null }
+ *   null       → Default-Voice (kdmDKE6EkgrWrrykO9Qt, Alexandra)
+ *   iFSsEDGbm0FiEd2IVH4w → Voice 1
+ *   Gt7OshJCH7MuzX96wFHi → Voice 2
+ *
+ * Plan-Downgrade-Verhalten: DB-Wert wird NICHT gelöscht. speak.post.ts
+ * prüft plan zur Laufzeit — non-legend User erhalten Default-Voice.
+ */
+export default defineEventHandler(async (event) => {
+  const user = await requireUser(event);
+
+  const db = usePrisma();
+  const profile = await db.profile.findUnique({
+    where: { id: user.id },
+    select: { plan: true },
+  });
+
+  if (!profile) {
+    throw createError({ statusCode: 404, statusMessage: "profile_not_found" });
+  }
+
+  if ((profile.plan ?? "free").toLowerCase() !== "legend") {
+    throw createError({ statusCode: 403, statusMessage: "legend_only" });
+  }
+
+  const body = await readBody(event);
+  const { lyraVoiceId } = body as { lyraVoiceId?: unknown };
+
+  if (!isAllowedLyraVoiceId(lyraVoiceId)) {
+    throw createError({ statusCode: 400, statusMessage: "invalid_voice_id" });
+  }
+
+  await setLyraVoiceId(user.id, lyraVoiceId);
+
+  return { success: true, data: { lyraVoiceId } };
+});

backend/server/db/profile.ts

@@ -204,6 +204,29 @@ export async function tryAwardProTrial(
   });
 }
 
+// ─── Lyra Voice-Picker ────────────────────────────────────────────────────
+
+const ALLOWED_LYRA_VOICE_IDS = [
+  null,
+  "iFSsEDGbm0FiEd2IVH4w", // Voice 1
+  "Gt7OshJCH7MuzX96wFHi", // Voice 2
+] as const;
+
+export type LyraVoiceId = (typeof ALLOWED_LYRA_VOICE_IDS)[number];
+
+export function isAllowedLyraVoiceId(value: unknown): value is LyraVoiceId {
+  return (ALLOWED_LYRA_VOICE_IDS as readonly unknown[]).includes(value);
+}
+
+export async function setLyraVoiceId(userId: string, voiceId: LyraVoiceId) {
+  const db = usePrisma();
+  return db.profile.update({
+    where: { id: userId },
+    data: { lyraVoiceId: voiceId },
+    select: { lyraVoiceId: true },
+  });
+}
+
 // ─── Banner / Install-Event ────────────────────────────────────────────────
 
 export async function dismissDigaBanner(userId: string) {