fix(tests): strengthen checksum verification assertion against regression (#48)

* Initial plan

* fix(tests): strengthen checksum test assertion to guard against regression

Co-authored-by: jamesadevine <4742697+jamesadevine@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jamesadevine <4742697+jamesadevine@users.noreply.github.com>

Author: Copilot

tests/compiler_tests.rs

@@ -148,6 +148,10 @@ fn test_compiled_yaml_structure() {
         template_content.contains("sha256sum -c checksums.txt --ignore-missing"),
         "Template should verify checksum using checksums.txt"
     );
+    assert!(
+        !template_content.contains("grep -q"),
+        "Checksum verification should not pipe through grep"
+    );
 
     // Verify AWF (Agentic Workflow Firewall) is downloaded from GitHub Releases, not ADO pipeline artifacts
     assert!(