Fix tests to skip when AWS credentials are not available

- Add credential check to status and destroy tests
- Tests now skip gracefully in CI environments without AWS creds
- Prevents false failures while preserving integration test functionality
- Tests still run when AWS credentials are present

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: dan-v

cmd/lambda-nat-proxy/cli_test.go

@@ -148,11 +148,17 @@ func testStatusCommand(t *testing.T) {
 	cmd.Dir = "."
 
 	output, err := cmd.CombinedOutput()
+	outputStr := string(output)
+	
+	// Skip test if AWS credentials are not available
+	if err != nil && strings.Contains(outputStr, "invalid AWS credentials") {
+		t.Skip("Skipping status test - AWS credentials not available")
+		return
+	}
+	
 	if err != nil {
 		t.Fatalf("Status command failed: %v\nOutput: %s", err, output)
 	}
-	
-	outputStr := string(output)
 	expectedStrings := []string{
 		"Lambda NAT Proxy Status",
 		"Overall Status:",
@@ -223,6 +229,13 @@ func testDestroyCommand(t *testing.T) {
 	// The command should exit with non-zero status when cancelled, but that's expected
 
 	outputStr := string(output)
+	
+	// Skip test if AWS credentials are not available
+	if strings.Contains(outputStr, "invalid AWS credentials") {
+		t.Skip("Skipping destroy test - AWS credentials not available")
+		return
+	}
+	
 	expectedStrings := []string{
 		"Lambda NAT Proxy Destruction Plan",
 		"The following resources will be PERMANENTLY DELETED:",