Add voice buttons, Wi-Fi netconfig, and demo STT server

demo-server/Dockerfile

@@ -0,0 +1,20 @@
+FROM python:3.12-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+        ffmpeg \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY app ./app
+COPY templates ./templates
+COPY static ./static
+
+ENV HOST=0.0.0.0
+ENV PORT=5000
+EXPOSE 5000
+
+CMD ["sh", "-c", "uvicorn app.main:app --host ${HOST} --port ${PORT}"]