feat: Remove Caddy and Docker configuration; add Express server with health checker endpoint

Dockerfile

@@ -0,0 +1,15 @@
+FROM node:20-alpine
+
+# Install only production dependencies
+WORKDIR /app
+COPY package.json ./
+
+# npm install will run inside Coolify/Traefik containers where network access exists
+RUN npm install --omit=dev
+
+# Copy the rest of the repository
+COPY . .
+
+EXPOSE 3000
+
+CMD ["npm", "start"]