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/parakeet/compose.yaml

@@ -0,0 +1,67 @@
+# Parakeet ASR — NVIDIA Parakeet-TDT 0.6B v2 speech-to-text.
+#
+# Wraps Shadowfita/parakeet-tdt-0.6b-v2-fastapi (FastAPI + Silero VAD +
+# WebSocket streaming). Upstream provides no prebuilt image, so we
+# build from a pinned git commit via docker buildx's git URL context
+# — no source files vendored into this repo.
+#
+# Runs on irv-ml1 (dual GPU). Both GPUs exposed; upstream respects
+# CUDA_VISIBLE_DEVICES if you want to pin later.
+#
+# HF weights (~2.5 GB for parakeet-tdt-0.6b-v2) cache to
+# ${PARAKEET_MODELS_DIR} via HF_HOME=/models, persistent across
+# container recreates.
+#
+# API routes (per upstream README):
+#   POST /transcribe          — batch transcription
+#   WS   /ws/transcribe       — streaming with Silero VAD
+#   GET  /healthz
+#
+# Not a literal OpenAI `/v1/audio/transcriptions` path; point clients
+# at /transcribe directly, or add a reverse-proxy alias if drop-in
+# compat is needed later.
+#
+# First `up` triggers a fresh docker build (python:3.10-slim +
+# torch + NeMo ≈ 5–10 min). Subsequent starts reuse the cached
+# image unless PARAKEET_SHA changes.
+#
+# All tunables live in .env — edit that, not this file.
+
+services:
+  parakeet:
+    image: local/parakeet:${PARAKEET_SHA}
+    build:
+      context: https://github.com/Shadowfita/parakeet-tdt-0.6b-v2-fastapi.git#${PARAKEET_SHA}
+    container_name: parakeet
+    restart: unless-stopped
+    runtime: nvidia
+    ports:
+      - "${PARAKEET_BIND:-0.0.0.0}:${PARAKEET_PORT}:8000"
+    environment:
+      - NVIDIA_VISIBLE_DEVICES=all
+      - HF_HOME=/models
+      - DEVICE=cuda
+      - MODEL_PRECISION=${PARAKEET_MODEL_PRECISION:-fp16}
+      - BATCH_SIZE=${PARAKEET_BATCH_SIZE:-4}
+      - TARGET_SAMPLE_RATE=16000
+      - MAX_AUDIO_DURATION=${PARAKEET_MAX_AUDIO_DURATION:-30}
+      - VAD_THRESHOLD=${PARAKEET_VAD_THRESHOLD:-0.5}
+      - PROCESSING_TIMEOUT=${PARAKEET_PROCESSING_TIMEOUT:-60}
+      - LOG_LEVEL=${PARAKEET_LOG_LEVEL:-INFO}
+    volumes:
+      - ${PARAKEET_MODELS_DIR}:/models
+    healthcheck:
+      test: ["CMD-SHELL", "curl -fsS http://localhost:8000/healthz >/dev/null || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      # First `up` may spend several minutes on torch/NeMo install
+      # during the image build phase; after the image exists, startup
+      # is ~30-60s (NeMo model load).
+      start_period: 180s
+    labels:
+      - homepage.group=AI Systems
+      - homepage.name=Parakeet ASR
+      - homepage.icon=mdi-microphone
+      - homepage.description=Parakeet-TDT speech-to-text (irv-ml1)
+      - homepage.href=http://10.100.79.3:${PARAKEET_PORT}