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>

firmware/sdkconfig.defaults

@@ -0,0 +1,14 @@
+# Target: Waveshare ESP32-P4-WIFI6-Touch-LCD-3.4C
+CONFIG_IDF_TARGET="esp32p4"
+
+# 32 MB NOR flash
+CONFIG_ESPTOOLPY_FLASHSIZE_32MB=y
+CONFIG_PARTITION_TABLE_SINGLE_APP_LARGE=y
+
+# 32 MB in-package PSRAM (hex mode) — LVGL frame buffers live here
+CONFIG_SPIRAM=y
+CONFIG_SPIRAM_MODE_HEX=y
+CONFIG_SPIRAM_SPEED_200M=y
+
+CONFIG_COMPILER_OPTIMIZATION_PERF=y
+CONFIG_FREERTOS_HZ=1000