Fix build process and add production build support

🔧 Build Process Improvements:
- Update default 'build' target to use development mode
- Add new 'build-prod' target for production builds with validation
- Fix 'deploy-prod-quick' to use production build command
- Update 'build-test' to use development build (safer for CI)

📚 Documentation:
- Add comprehensive Production Build Guide (docs/deployment/PRODUCTION_BUILD.md)
- Include security requirements, configuration methods, and troubleshooting
- Update main documentation index with production build guide
- Update README with both build command options

✨ Features:
- Development builds work without security configuration
- Production builds require proper JWT/SESSION secrets
- Clear separation between dev and prod build processes
- Comprehensive production deployment documentation

🔒 Security:
- Enforced JWT_SECRET validation for production builds
- Clear documentation of required security configurations
- Examples for CI/CD integration with proper secret management
- Best practices for production deployment

🧪 Verification:
- ✅ Development build: make build (works with warnings)
- ✅ Production build validation: make build-prod (fails without secrets)
- ✅ Production build with secrets: works correctly
- ✅ All existing functionality preserved

Makefile

@@ -37,8 +37,12 @@ dev: ## Start development server
 	@printf "$(BLUE)Starting development server...$(RESET)\n"
 	@bun run dev
 
-build: ## Build the application
-	@printf "$(BLUE)Building application...$(RESET)\n"
+build: ## Build the application for development
+	@printf "$(BLUE)Building application for development...$(RESET)\n"
+	@NODE_ENV=development bun run build
+
+build-prod: ## Build the application for production
+	@printf "$(BLUE)Building application for production...$(RESET)\n"
 	@bun run build
 
 preview: ## Preview the built application
@@ -202,7 +206,7 @@ build-test: build test ## Build and run unit tests
 deploy-dev-quick: build deploy-dev ## Build and deploy to development
 	@printf "$(GREEN)Quick development deployment completed!$(RESET)\n"
 
-deploy-prod-quick: build deploy-prod ## Build and deploy to production
+deploy-prod-quick: build-prod deploy-prod ## Build and deploy to production
 	@printf "$(GREEN)Quick production deployment completed!$(RESET)\n"
 
 undeploy-all: undeploy-dev undeploy-prod docker-clean ## Remove all deployments and clean Docker