fix: Use only dist folder (contains public assets)

- Astro build automatically copies public/ to dist/
- Remove separate public folder copy (not needed)
- Use PORT environment variable (default 80)
- Fix favicon 404 by using correct dist structure

Dockerfile

@@ -0,0 +1,40 @@
+# Astro Production Dockerfile
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci
+
+# Copy source code
+COPY . .
+
+# Build the project (public folder auto-copied to dist/)
+RUN npm run build
+
+# Production Stage
+FROM node:20-alpine
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install production dependencies only
+RUN npm ci --production
+
+# Copy ONLY the dist folder (contains build + public assets)
+COPY --from=builder /app/dist ./dist
+
+# Expose port
+EXPOSE ${PORT:-80}
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+  CMD node -e "require('http').get('http://localhost:${PORT:-80}', (r) => {process.exit(r.statusCode === 200 ? 0 : 1)})"
+
+# Start the server
+CMD ["sh", "-c", "npx astro preview --host 0.0.0.0 --port ${PORT:-80}"]