fix: add circuit breaker basic template failure pattern

- Include 'Mock circuit breaker: operation failed' pattern
- Fixes Template Validation Pipeline for circuit-breaker-basic-template
- This template is designed to demonstrate failure handling by design

Author: Tom Brandenburg

Makefile

@@ -131,7 +131,7 @@ templates-all: build
 					     ! grep -q "bash:.*invalid variable name\|syntax error\|command not found.*get_var" "$$result_file"; then \
 						echo "  ✅ Expected behavior - template works (requires environment/template variables)"; \
 						success=$$((success + 1)); \
-					elif grep -q "Mock circuit breaker.*operation failed\|Circuit breaker operation failed" "$$result_file" && \
+					elif grep -q "Mock circuit breaker.*operation failed\|Circuit breaker operation failed\|Mock circuit breaker: operation failed" "$$result_file" && \
 					     ! grep -q "bash:.*invalid variable name\|syntax error\|command not found.*get_var" "$$result_file"; then \
 						echo "  ✅ Expected behavior - circuit breaker demonstrating failure handling"; \
 						success=$$((success + 1)); \