deploy/mainnet: add PiperTTS (private) + supplier-tts (audio.synthesize.piper.v1)

Mirrors deploy/testnet/docker-compose.supplier-tts.yml and the simulation
PiperTTS stack, co-located on vector-marketplace as a private internal
service on marketplace-mainnet-net (no Traefik labels, no public DNS for
Piper itself). Supplier reaches Piper at http://marketplace-mainnet-tts-piper:8000.
Voice: en_US-lessac-high. New supplier wallet + on-chain advert are
published out-of-band by the operator per the runbook header.

Files:
- deploy/mainnet/docker-compose.tts-piper.yml         openedai-speech-min, private
- deploy/mainnet/docker-compose.supplier-tts.yml      CAPABILITY_KIND=tts supplier
- deploy/mainnet/install-voice-extras.sh              voice download + yaml mapping
- deploy/mainnet/voice-mappings.py                    idempotent yaml editor
- supplier/.env.tts.example                           operator env template
- .gitignore                                          whitelist .env.*.example

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

deploy/mainnet/voice-mappings.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+# voice-mappings.py — idempotently apply project-specific voice aliases to
+# /app/config/voice_to_speaker.yaml inside the marketplace-mainnet-tts-piper container.
+#
+# Why this exists:
+#   The openedai-speech-min image populates voice_to_speaker.yaml on first
+#   start with its OWN defaults (alloy/echo/fable/onyx/nova/shimmer mapped
+#   onto the bundled LibriTTS + northern-english-male voices). Voices we
+#   install ourselves (e.g. en_US-lessac-high) need a name in that yaml so
+#   the OpenAI-shape `voice` field can resolve to them. This script adds
+#   those entries — and only those — without disturbing the defaults.
+#
+# Idempotency contract:
+#   Reads the yaml, compares each desired entry against what's there, only
+#   rewrites if at least one entry is missing or stale. Prints "modified"
+#   on write, "unchanged" otherwise — install-voice-extras.sh greps for
+#   "modified" to decide whether to restart the container.
+#
+# Run via:
+#   docker cp voice-mappings.py marketplace-mainnet-tts-piper:/tmp/voice-mappings.py
+#   docker exec marketplace-mainnet-tts-piper python3 /tmp/voice-mappings.py
+
+import sys
+import yaml
+
+CONFIG_PATH = "/app/config/voice_to_speaker.yaml"
+
+# Mappings to ensure exist under `tts-1`. Adding more voices later is a
+# matter of dropping the .onnx + .onnx.json into voices/ (handled by
+# install-voice-extras.sh) and adding an entry here.
+DESIRED_TTS1 = {
+    # en_US-lessac-high — high-quality American female single-speaker voice.
+    # Single-speaker model, so no `speaker:` key.
+    "lessac": {"model": "voices/en_US-lessac-high.onnx"},
+}
+
+
+def main() -> int:
+    with open(CONFIG_PATH) as f:
+        cfg = yaml.safe_load(f) or {}
+
+    cfg.setdefault("tts-1", {})
+
+    modified_keys = []
+    for name, mapping in DESIRED_TTS1.items():
+        if cfg["tts-1"].get(name) != mapping:
+            cfg["tts-1"][name] = mapping
+            modified_keys.append(name)
+
+    if modified_keys:
+        with open(CONFIG_PATH, "w") as f:
+            yaml.safe_dump(cfg, f, sort_keys=False)
+        print(f"modified — applied: {', '.join(modified_keys)}")
+    else:
+        print("unchanged — all mappings already present")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())