fix(backend): change to backend directory in Dockerfile

- Added WORKDIR /app/backend before npm run build

- Updated COPY commands to use /app/backend/ paths

Author: Your Name

backend/Dockerfile

@@ -21,18 +21,19 @@ COPY . .
 # Generate Prisma client with workspace root path
 RUN npx prisma generate --schema=backend/prisma/schema.prisma
 
-# Build TypeScript to JavaScript
+# Change to backend directory and build
+WORKDIR /app/backend
 RUN npm run build
 
 # Stage 2: Production stage
 FROM node:20-alpine
 
 WORKDIR /app
 
-# Copy production dependencies and built files
-COPY --from=builder /app/package*.json ./
-COPY --from=builder /app/dist ./dist
-COPY --from=builder /app/node_modules ./node_modules
+# Copy production dependencies and built files from backend
+COPY --from=builder /app/backend/package*.json ./
+COPY --from=builder /app/backend/dist ./dist
+COPY --from=builder /app/backend/node_modules ./node_modules
 COPY --from=builder /app/backend/prisma ./prisma
 COPY --from=builder /app/backend/src/generated ./src/generated