Add XTTS primary voice with Piper fallback

compose.yaml

@@ -529,7 +529,11 @@ services:
       CHAT_IMAGE_ALLOW_REMOTE_URLS: "false"
       ENABLE_IMAGE_GENERATION: "true"
       ENABLE_TTS: "true"
-      TTS_WORKER_URL: http://piper:8085
+      # Stable OpenAI compatibility names remain piper/alloy because an
+      # existing Open WebUI database persists those values. The gateway maps
+      # alloy to XTTS speaker Annmarie Nele and automatically falls back to
+      # Piper if XTTS is unavailable, busy or returns an error.
+      TTS_WORKER_URL: http://tts-gateway:8085
       TTS_MODEL: piper
       TTS_VOICES: alloy
       TTS_DEFAULT_VOICE: alloy
@@ -555,6 +559,8 @@ services:
         condition: service_healthy
       piper:
         condition: service_healthy
+      tts-gateway:
+        condition: service_healthy
 
   flux-worker:
     build:
@@ -622,6 +628,74 @@ services:
       retries: 30
       start_period: 120s
 
+  xtts:
+    image: ${XTTS_IMAGE:-ghcr.io/coqui-ai/xtts-streaming-server:latest-cuda121@sha256:f7fb3b1f9d4bc88af94da1b5959d8002f1e0b003c97557164034eb8a29f01b90}
+    container_name: mike-ai-xtts
+    restart: unless-stopped
+    deploy:
+      resources:
+        reservations:
+          devices:
+            - driver: nvidia
+              device_ids:
+                - ${XTTS_GPU_DEVICE:-GPU-4834d9d7-5b61-3004-1fb3-4ae49d482d4b}
+              capabilities: [gpu]
+    read_only: true
+    shm_size: 1g
+    tmpfs:
+      - /tmp:size=1g,mode=1777
+      - /root/.cache:size=2g,mode=0700
+    volumes:
+      - "${XTTS_CACHE_DIR:-/data/models/xtts-v2-cache}:/root/.local/share/tts"
+    environment:
+      COQUI_TOS_AGREED: "1"
+      NVIDIA_VISIBLE_DEVICES: ${XTTS_GPU_DEVICE:-GPU-4834d9d7-5b61-3004-1fb3-4ae49d482d4b}
+      NVIDIA_DRIVER_CAPABILITIES: compute,utility
+      CUDA_VISIBLE_DEVICES: "0"
+      NUM_THREADS: "4"
+    networks: [frontend]
+    security_opt: ["no-new-privileges:true"]
+    cap_drop: [ALL]
+    healthcheck:
+      test: [CMD, curl, -fsS, "http://127.0.0.1/languages"]
+      interval: 10s
+      timeout: 5s
+      retries: 36
+      start_period: 240s
+
+  tts-gateway:
+    build:
+      context: platform/docker/tts-gateway
+    image: mike-ai/tts-gateway:local
+    container_name: mike-ai-tts-gateway
+    restart: unless-stopped
+    read_only: true
+    tmpfs:
+      - /tmp:size=256m,mode=1777
+    environment:
+      TTS_GATEWAY_HOST: 0.0.0.0
+      TTS_GATEWAY_PORT: "8085"
+      XTTS_URL: http://xtts:80
+      PIPER_URL: http://piper:8085
+      TTS_VOICE_ALIAS: alloy
+      XTTS_SPEAKER: Annmarie Nele
+      TTS_DEFAULT_LANGUAGE: de
+      XTTS_QUEUE_TIMEOUT: "15"
+      XTTS_TIMEOUT: "120"
+      PIPER_TIMEOUT: "120"
+    networks: [frontend]
+    depends_on:
+      piper:
+        condition: service_healthy
+    security_opt: ["no-new-privileges:true"]
+    cap_drop: [ALL]
+    healthcheck:
+      test: [CMD, curl, -fsS, "http://127.0.0.1:8085/status"]
+      interval: 10s
+      timeout: 5s
+      retries: 12
+      start_period: 10s
+
   open-webui:
     image: ${OPENWEBUI_IMAGE:-ghcr.io/open-webui/open-webui:v0.9.5}
     container_name: mike-ai-open-webui