feat: add Dockerfile and GitHub Actions workflow for GHCR deployment

Dockerfile

@@ -0,0 +1,38 @@
+# Stage 1: Build
+FROM node:20-slim AS build
+
+WORKDIR /app
+
+# Install build dependencies
+COPY package*.json ./
+RUN npm ci
+
+# Copy source and build frontend
+COPY . .
+RUN npm run build
+
+# Stage 2: Runtime
+FROM node:20-slim AS runtime
+
+# Set production environment
+ENV NODE_ENV=production
+ENV PORT=3000
+ENV ARCHIVES_DIR=/archives
+
+WORKDIR /app
+
+# Install runtime dependencies only
+COPY package*.json ./
+RUN npm ci --omit=dev
+
+# Copy built assets and server
+COPY --from=build /app/dist ./dist
+COPY --from=build /app/server.ts ./
+
+# Ensure archives directory exists
+RUN mkdir -p /archives
+
+EXPOSE 3000
+
+# Start server using tsx
+CMD ["npx", "tsx", "server.ts"]