Initial scaffold: ESP32-P4 firmware + voice gateway for Tatlock endpoint

DeskLock gives the Tatlock butler a face and voice on a Waveshare
ESP32-P4-WIFI6-Touch-LCD-3.4C round display in the living room.

- firmware/: ESP-IDF project targeting esp32p4 with the Waveshare XC BSP
- gateway/: FastAPI voice bridge (faster-whisper STT, Tatlock chat, Piper TTS)
- docs/architecture.md: component design and device<->gateway WS protocol

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

gateway/Dockerfile

@@ -0,0 +1,10 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+COPY pyproject.toml ./
+COPY src ./src
+RUN pip install --no-cache-dir ".[speech]"
+
+EXPOSE 8600
+CMD ["uvicorn", "desklock_gateway.main:app", "--host", "0.0.0.0", "--port", "8600"]