feat: integrate Tailwind CSS for improved styling and layout

- Added Tailwind CSS and its Vite plugin to the frontend project.
- Updated App.svelte to enhance UI with Tailwind classes, including a new layout for the serial monitor and command tester.
- Improved logging functionality by increasing log history and adding more detailed log messages.
- Refactored SendBox.svelte for consistent styling with Tailwind.
- Enhanced Pico firmware to support structured event logging and command parsing.
- Updated README_PICO_SERIAL.md to provide comprehensive documentation on serial communication and backend integration.
- Added .dockerignore to optimize Docker builds by excluding unnecessary files.

frontend/Dockerfile

@@ -1,20 +1,48 @@
-# Multi-stage build for SvelteKit (static client + node server fallback)
-FROM node:20-bookworm-slim AS builder
-WORKDIR /app
+######## Combined Frontend + Backend build (single Node runtime) ########
+# This Dockerfile now builds BOTH the Svelte frontend and the NestJS backend
+# and serves the compiled frontend through the backend (Express static).
 
-# Install deps (use package-lock if present)
-COPY package*.json ./
+########################
+# 1) Frontend build     #
+########################
+FROM node:20-bookworm-slim AS frontend-build
+WORKDIR /frontend
+COPY frontend/package*.json ./
 RUN npm install --no-audit --no-fund
-
-# Copy sources and build
-COPY . .
+COPY frontend/ .
 RUN npm run build
 
-# Use a lightweight nginx to serve the client build output
-FROM nginx:alpine AS runner
-COPY --from=builder /app/dist /usr/share/nginx/html
+########################
+# 2) Backend build      #
+########################
+FROM node:20-bookworm-slim AS backend-build
+WORKDIR /app
+COPY backend/package*.json ./
+RUN npm install --no-audit --no-fund
+COPY backend/ .
+# Copy compiled frontend into backend/public (served statically by Nest)
+COPY --from=frontend-build /frontend/dist ./public
+RUN npm run build
 
-# Default nginx port
-EXPOSE 80
+########################
+# 3) Production image   #
+########################
+FROM node:20-bookworm-slim AS runner
+ENV NODE_ENV=production
+WORKDIR /app
 
-CMD ["nginx", "-g", "daemon off;"]
+# Install only production deps (reuse original package.json)
+COPY backend/package*.json ./
+RUN npm install --omit=dev --no-audit --no-fund
+
+# Copy backend dist + public assets
+COPY --from=backend-build /app/dist ./dist
+COPY --from=backend-build /app/public ./public
+
+# Environment (override at runtime as needed)
+ENV PORT=3000 \
+	SERIAL_BAUD=115200
+
+EXPOSE 3000
+
+CMD ["node", "dist/main.js"]