fix: switch Dockerfile to bun and copy bun.lock

Co-authored-by: aider (openrouter/thinkingmachines/inkling-small:free) <aider@aider.chat>

Dockerfile

@@ -6,8 +6,9 @@ FROM node:22-alpine AS builder
 WORKDIR /app
 
 # Install dependencies first (layer caching)
-COPY package.json ./
-RUN npm install
+COPY package.json bun.lock ./
+RUN npm install -g bun
+RUN bun install
 
 # Copy application source code
 COPY . .
@@ -17,7 +18,7 @@ ARG VITE_GOOGLE_MAPS_API_KEY=""
 ENV VITE_GOOGLE_MAPS_API_KEY=$VITE_GOOGLE_MAPS_API_KEY
 
 # Build production bundle (Vite client + server.cjs)
-RUN npm run build
+RUN bun run build
 
 # ========================================================
 # Stage 2: Serve full-stack application (API + SPA) with Node.js
@@ -29,8 +30,9 @@ ENV NODE_ENV=production
 ENV PORT=3000
 
 # Install production dependencies only
-COPY package.json ./
-RUN npm install --omit=dev && npm cache clean --force
+COPY package.json bun.lock ./
+RUN npm install -g bun
+RUN bun install --production
 
 # Copy built bundle from builder stage
 COPY --from=builder /app/dist ./dist