parakeet + cosyvoice: add stacks + deploy to irv-ml1

Two new speech stacks on irv-ml1, both on the /worktank/<stack>/
pattern, no tnet (irv-ml1 is local-endpoints-only for now).

parakeet — ASR via Shadowfita/parakeet-tdt-0.6b-v2-fastapi:
  - docker buildx git context pinned to SHA 31c5652; no source
    vendored. Rebuild on SHA bump.
  - GPU-capable FastAPI + Silero VAD + WS streaming.
  - API: POST /transcribe, WS /ws/transcribe, GET /healthz. Not the
    literal OpenAI `/v1/audio/transcriptions` path — note in README.
  - HF cache at /worktank/parakeet/models/ (excluded from restic).
  - Build ~158s first time; steady-state start ~40s.

cosyvoice — TTS via neosun/cosyvoice:v1.3.2 shipping
Fun-CosyVoice3-0.5B-2512 (CosyVoice 3, chosen over v2 for the
expanded 5,000-hour instruction-following data covering emotions,
speed, tones, dialects, accents, role-playing; ~150ms streaming
TTFB matches v2). API: /v1/audio/speech (OpenAI drop-in),
/v1/voices/create (cloning), /health.
  - Host port 8190 (container 8188; host 8188 already taken by comfyui).
  - /worktank/cosyvoice/{voices,input,output}/; voices include in
    restic (precious — reproducing a clone needs the original ref
    audio), input+output excluded (scratch).
  - Model weights (~2-3 GB) live inside image layer; re-download on
    tag bump, persist across `compose up -d`.

Both healthy on first deploy.

stacks/cosyvoice/compose.yaml

@@ -0,0 +1,60 @@
+# CosyVoice — multilingual expressive TTS with voice cloning.
+#
+# Ships the Fun-CosyVoice3-0.5B-2512 model from FunAudioLLM (latest
+# as of 2026-04). Streaming PCM chunks with ~150 ms TTFB. Emotional
+# control via either XML tags (<angry>text</angry>) or instruction
+# prompts (`You are a helpful assistant. <|endofprompt|>` syntax).
+#
+# Runs on irv-ml1 (dual GPU). Both GPUs exposed via
+# NVIDIA_VISIBLE_DEVICES=all; image reads CUDA_VISIBLE_DEVICES if
+# you later want to pin.
+#
+# Path split:
+#   /worktank/cosyvoice/voices  → /data/voices   cloned speaker profiles
+#   /worktank/cosyvoice/input   → /data/input    scratch for uploaded source audio
+#   /worktank/cosyvoice/output  → /data/output   synthesized clips
+#
+# Models (~2–3 GB) download on first run into the image's internal
+# pretrained_models/ path. Not bind-mounted (the image expects an
+# exact layout we don't have authoritative docs for); recreating the
+# container without the cached image will re-download. Cached image
+# layer persists through `compose up -d` recreates.
+#
+# API routes (OpenAI-compatible where marked):
+#   POST /v1/audio/speech         — OpenAI drop-in for TTS
+#   POST /v1/voices/create        — voice cloning (reference audio in)
+#   GET  /v1/voices               — list cloned voices
+#   GET  /health                  — health probe
+#
+# All tunables live in .env — edit that, not this file.
+
+services:
+  cosyvoice:
+    image: neosun/cosyvoice:${COSYVOICE_VERSION}
+    container_name: cosyvoice
+    restart: unless-stopped
+    runtime: nvidia
+    ports:
+      - "${COSYVOICE_BIND:-0.0.0.0}:${COSYVOICE_PORT}:8188"
+    environment:
+      - NVIDIA_VISIBLE_DEVICES=all
+      - MODEL_DIR=${COSYVOICE_MODEL_DIR:-pretrained_models/Fun-CosyVoice3-0.5B}
+      - PORT=8188
+      - GPU_IDLE_TIMEOUT=${COSYVOICE_GPU_IDLE_TIMEOUT:-600}
+    volumes:
+      - ${COSYVOICE_VOICES_DIR}:/data/voices
+      - ${COSYVOICE_INPUT_DIR}:/data/input
+      - ${COSYVOICE_OUTPUT_DIR}:/data/output
+    healthcheck:
+      test: ["CMD-SHELL", "curl -fsS http://localhost:8188/health >/dev/null || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      # First boot pulls ~2–3 GB of model weights.
+      start_period: 300s
+    labels:
+      - homepage.group=AI Systems
+      - homepage.name=CosyVoice
+      - homepage.icon=mdi-account-voice
+      - homepage.description=Expressive multilingual TTS + cloning (irv-ml1)
+      - homepage.href=http://10.100.79.3:${COSYVOICE_PORT}