Fix Docker build: Install dev dependencies for build process

🔧 Critical Fix:
- Remove --only=production from client build stage (needs devDependencies)
- Remove --only=production from server build stage (needs TypeScript, etc.)
- Add production dependencies install in final stage only
- Remove duplicate npm ci commands

🏗️ Build Process Fixed:
- Client: npm ci (all deps) → build with TypeScript/Vite → copy dist/
- Server: npm ci (all deps) → build with TypeScript → copy dist/
- Production: Install only runtime dependencies for final image

⚡ Why This Fixes It:
- Build tools (TypeScript, Vite) are devDependencies
- --only=production excludes build tools, causing 'npm run build' to fail
- Final production stage still gets minimal runtime dependencies

This should resolve the 'npm run build exit code 127' Docker build error.

Dockerfile

@@ -6,7 +6,7 @@ WORKDIR /app/client
 
 # Copy client package files
 COPY client/package*.json ./
-RUN npm ci --only=production
+RUN npm ci
 
 # Copy client source and build
 COPY client/ ./
@@ -18,7 +18,7 @@ WORKDIR /app/server
 
 # Copy server package files
 COPY server/package*.json ./
-RUN npm ci --only=production
+RUN npm ci
 
 # Copy server source and build
 COPY server/ ./
@@ -35,11 +35,15 @@ RUN apk add --no-cache dumb-init curl
 RUN addgroup -g 1001 -S nodejs
 RUN adduser -S nodejs -u 1001
 
-# Copy built server
-COPY --from=server-build --chown=nodejs:nodejs /app/server/dist ./server/
-COPY --from=server-build --chown=nodejs:nodejs /app/server/node_modules ./server/node_modules/
+# Copy server package files for production dependencies
 COPY --from=server-build --chown=nodejs:nodejs /app/server/package*.json ./server/
 
+# Install only production dependencies
+RUN cd server && npm ci --only=production && cd ..
+
+# Copy built server
+COPY --from=server-build --chown=nodejs:nodejs /app/server/dist ./server/dist/
+
 # Copy built client for nginx sharing
 COPY --from=client-build --chown=nodejs:nodejs /app/client/dist ./client/dist/