stacks: add Kokoro, VibeVoice 1.5B, Chatterbox Turbo (TTS slate fill-in)

Three TTS additions to round out coverage on irv-ml1, each filling a
distinct niche the existing slate doesn't own.

Final coverage matrix (all on irv-ml1):
  Kokoro              — low-latency English, fixed voice library, ~300ms TTFA
  Chatterbox Turbo    — low-latency English w/ voice cloning + paralinguistic tags
  IndexTTS-2          — English voice cloning + emotion vector / text control
  Qwen3-TTS-1.7B-Base — high-quality English voice cloning
  CosyVoice 3         — multilingual (Chinese-leaning)
  VibeVoice 1.5B      — long-form / multi-speaker dialogue

stacks/kokoro:
  - port 8193, GPU device 0 (3090)
  - pulls ghcr.io/remsky/kokoro-fastapi-gpu:v0.2.4-master (no Dockerfile,
    no first-run model download — models baked in)
  - 60+ built-in voices, OpenAI-compat with stream=true over chunked HTTP
  - Apache-2.0 weights + code, ~1 GB VRAM

stacks/vibevoice:
  - port 8194, GPU device 1 (A6000 — for 7B headroom)
  - builds groxaxo/VibeVoice-FastAPI1 (more current fork of ncoder-ai)
    pinned to 7614c469a145
  - default model microsoft/VibeVoice-1.5B (~7 GB bf16 VRAM); env var
    swap to rsxdalv/VibeVoice-Large (7B) or FabioSarracino/VibeVoice-Large-Q8
  - multi-speaker dialogue via /v1/vibevoice/generate with Speaker N: format
  - long-form niche only — not low-latency

stacks/chatterbox:
  - port 8196, GPU device 0 (3090)
  - builds devnen/Chatterbox-TTS-Server (most active Turbo-supporting wrapper)
  - default model ResembleAI/chatterbox-turbo (~2.5 GB fp16, ~75ms latency)
  - paralinguistic tags inline ([laugh] [whisper] etc) — different shape
    from IndexTTS-2's emotion vector; fills the speed+cloning niche
    Kokoro/IndexTTS don't cover together
  - mandatory PerTh watermark on outputs (Resemble policy)

Three matching playbooks under playbooks/deploy-{kokoro,vibevoice,
chatterbox}.yaml. All idempotent, creates-/when-gated.

Cold-deploy disk on /worktank/: ~7 GB Kokoro + ~19 GB VibeVoice 1.5B
+ ~12 GB Chatterbox = ~38 GB total. VRAM concurrent: ~10-11 GB across
both GPUs.

Skipped from the original four-stack proposal: VibeVoice Realtime
(overlaps Kokoro's niche; Kokoro wins on latency, license, and not
needing a build).

stacks/chatterbox/compose.yaml

@@ -0,0 +1,60 @@
+# Chatterbox Turbo (Resemble AI's 350M-param low-latency English TTS
+# with zero-shot voice cloning) served via devnen/Chatterbox-TTS-Server
+# — the most actively-maintained OpenAI-compat wrapper that supports
+# the Turbo checkpoint.
+#
+# Why this stack exists alongside the other TTS:
+#   * Low-latency English with VOICE CLONING (Kokoro is fast but
+#     fixed-voice; this fills the speed-AND-cloning slot).
+#   * Native paralinguistic tags inline in text:
+#       [laugh] [cough] [sigh] [gasp] [whisper] [breath]
+#     Different shape from IndexTTS-2's emotion vector — cleaner for
+#     "say it like this" markup directly in the prompt.
+#   * MIT weights + code; ~2.5 GB VRAM at fp16; ~75 ms latency.
+#   * Mandatory PerTh watermark on outputs (Resemble policy, can't
+#     be disabled). Non-issue for internal use.
+#
+# Image is built locally from the upstream Dockerfile via docker
+# buildx git-context (no source vendored on the host).
+#
+# All tunables live in .env — edit that, not this file.
+
+services:
+  chatterbox:
+    image: local/chatterbox:${CHATTERBOX_TAG}
+    build:
+      context: https://github.com/devnen/Chatterbox-TTS-Server.git#${CHATTERBOX_SHA}
+      dockerfile: docker/Dockerfile.gpu
+    container_name: chatterbox
+    restart: unless-stopped
+    runtime: nvidia
+    ports:
+      - "${CHATTERBOX_BIND:-0.0.0.0}:${CHATTERBOX_PORT}:8004"
+    environment:
+      - NVIDIA_VISIBLE_DEVICES=${CHATTERBOX_GPU_DEVICES:-0}
+      # Switch to ResembleAI/chatterbox-turbo (default) or the base
+      # ResembleAI/chatterbox / ResembleAI/chatterbox-multilingual
+      # via the wrapper's config hot-swap.
+      - CHATTERBOX_MODEL_REPO=${CHATTERBOX_MODEL_REPO:-ResembleAI/chatterbox-turbo}
+      - HF_HOME=/app/hf_cache
+    volumes:
+      - ${CHATTERBOX_REFERENCE_DIR}:/app/reference_audio
+      - ${CHATTERBOX_CACHE_DIR}:/app/hf_cache
+      # Optional: mount config.yaml as a host file for hot-edit. Default
+      # is to use the in-image config + env var overrides.
+      # - ${CHATTERBOX_CONFIG}:/app/config.yaml:ro
+    healthcheck:
+      # Devnen wrapper exposes /health; the OpenAPI/docs path is /docs.
+      test: ["CMD-SHELL", "curl -fsS -o /dev/null http://localhost:8004/health || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      # First boot pulls Chatterbox-Turbo (~6 GB total HF assets) and
+      # warms torch.compile — give it a generous deadline.
+      start_period: 600s
+    labels:
+      - homepage.group=AI Systems
+      - homepage.name=Chatterbox Turbo
+      - homepage.icon=mdi-account-music-outline
+      - homepage.description=Low-latency English TTS w/ voice cloning + paralinguistics (irv-ml1)
+      - homepage.href=http://10.100.79.3:${CHATTERBOX_PORT}