test: add integration test for issue #2291 (CRD preservation with strategicMergePatches) (#2292)

* test: add integration test for issue #2291 with all fixes

Add comprehensive integration test for issue #2291 that validates CRD
preservation when using strategicMergePatches with chartify.

Problem:
When using strategicMergePatches, chartify was relocating CRDs from
templates/crds/ to root crds/ directory, changing how Helm manages them.
This caused helm diff to incorrectly show CRDs as being removed, even
though they were still present.

Solution:
Chartify now preserves the original CRD location in templates/crds/.
This integration test validates the fix by:
1. Templating a chart with CRDs in templates/crds/
2. Applying the chart with strategicMergePatches
3. Verifying CRD is installed
4. Running helm diff to ensure CRD is NOT marked for removal
5. Verifying the strategic merge patch was applied

Additional fixes included in this commit:
- Fixed grep command error when matching YAML deletion patterns
- Updated expected test output for Helm 4 diff behavior
- Fixed EXIT trap interference between test cases
- Added --plain-http flag for Helm 4 OCI registry compatibility
- Ensured CRD templates are valid (cluster-scoped, no namespace)
- Fixed strategic merge patch namespace matching

Test coverage:
- CRD preservation in templates/crds/ subdirectory
- Strategic merge patch application
- Helm diff behavior with CRDs
- Integration with chartify kustomize processing

Fixes #2291

Signed-off-by: Aditya Menon <amenon@canarytechnologies.com>

* switch chartify package to upstream one

Signed-off-by: Aditya Menon <amenon@canarytechnologies.com>

* implement copilot suggestion

Signed-off-by: Aditya Menon <amenon@canarytechnologies.com>

---------

Signed-off-by: Aditya Menon <amenon@canarytechnologies.com>

test/integration/test-cases/issue-2247.sh

@@ -65,6 +65,7 @@ info "SUCCESS: OCI charts without version do not trigger validation error"
 if ! command -v docker &> /dev/null; then
   info "Skipping registry tests (Docker not available)"
   rm -rf "${issue_2247_tmp_dir}"
+  trap - EXIT
   test_pass "issue-2247: OCI charts without version (validation tests only)"
   return 0
 fi
@@ -73,6 +74,7 @@ fi
 if ! docker info &> /dev/null; then
   info "Skipping registry tests (Docker daemon not running)"
   rm -rf "${issue_2247_tmp_dir}"
+  trap - EXIT
   test_pass "issue-2247: OCI charts without version (validation tests only)"
   return 0
 fi
@@ -105,6 +107,7 @@ if [ $? -ne 0 ]; then
   cat "${issue_2247_tmp_dir}/registry-start.log"
   warn "Failed to start Docker registry - skipping registry tests"
   rm -rf "${issue_2247_tmp_dir}"
+  trap - EXIT
   test_pass "issue-2247: OCI charts without version (validation tests only)"
   return 0
 fi
@@ -125,6 +128,7 @@ done
 if [ $attempt -eq $max_attempts ]; then
   warn "Registry did not become ready in time - skipping registry tests"
   cleanup_registry
+  trap - EXIT
   test_pass "issue-2247: OCI charts without version (validation tests only)"
   return 0
 fi
@@ -138,6 +142,7 @@ if [ $? -ne 0 ]; then
   cat "${issue_2247_tmp_dir}/package.log"
   warn "Failed to package chart - skipping registry tests"
   cleanup_registry
+  trap - EXIT
   test_pass "issue-2247: OCI charts without version (validation tests only)"
   return 0
 fi
@@ -145,12 +150,14 @@ set -e  # Re-enable exit on error after successful package
 
 info "Pushing chart version 1.0.0 to local registry"
 set +e  # Disable exit on error to handle failures gracefully
-${helm} push "${issue_2247_tmp_dir}/test-chart-2247-1.0.0.tgz" oci://localhost:${registry_port} > "${issue_2247_tmp_dir}/push.log" 2>&1
+# Use --plain-http for localhost registry (HTTP instead of HTTPS)
+${helm} push "${issue_2247_tmp_dir}/test-chart-2247-1.0.0.tgz" oci://localhost:${registry_port} --plain-http > "${issue_2247_tmp_dir}/push.log" 2>&1
 if [ $? -ne 0 ]; then
   set -e  # Re-enable before cleanup
   cat "${issue_2247_tmp_dir}/push.log"
   warn "Failed to push chart to registry - skipping registry tests"
   cleanup_registry
+  trap - EXIT
   test_pass "issue-2247: OCI charts without version (validation tests only)"
   return 0
 fi
@@ -162,7 +169,7 @@ cp -r "${issue_2247_chart_dir}" "${issue_2247_tmp_dir}/chart-v2"
 sed -i.bak 's/version: 1.0.0/version: 2.0.0/' "${issue_2247_tmp_dir}/chart-v2/Chart.yaml"
 set +e  # Disable exit on error for package/push operations
 ${helm} package "${issue_2247_tmp_dir}/chart-v2" -d "${issue_2247_tmp_dir}" > "${issue_2247_tmp_dir}/package-v2.log" 2>&1
-${helm} push "${issue_2247_tmp_dir}/test-chart-2247-2.0.0.tgz" oci://localhost:${registry_port} > "${issue_2247_tmp_dir}/push-v2.log" 2>&1
+${helm} push "${issue_2247_tmp_dir}/test-chart-2247-2.0.0.tgz" oci://localhost:${registry_port} --plain-http > "${issue_2247_tmp_dir}/push-v2.log" 2>&1
 set -e  # Re-enable exit on error
 
 info "Successfully pushed chart versions 1.0.0 and 2.0.0"
@@ -270,4 +277,6 @@ else
 fi
 
 # All tests passed!
+# Remove the EXIT trap to avoid interfering with subsequent tests
+trap - EXIT
 test_pass "issue-2247: OCI charts without version (all tests including registry)"