test: use getter methods for license fields in install config tests

Updates test assertions to use GetLicenseID() and GetAppSlug() getter
methods instead of directly accessing license.Spec fields. This aligns
test code with production patterns and ensures tests work correctly with
both v1beta1 and v1beta2 license formats.

Changes:
- Line 649: license.Spec.LicenseID -> license.GetLicenseID()
- Line 650: license.Spec.AppSlug -> license.GetAppSlug()

This completes Phase 3 of the license v1beta2 support work, ensuring
test code follows the same defensive patterns as production code.

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

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

Author: crdant

cmd/installer/cli/install_config_test.go

@@ -646,8 +646,8 @@ spec:
 				if tt.expectLicense {
 					assert.NotEmpty(t, installCfg.licenseBytes, "License bytes should be populated")
 					assert.NotNil(t, installCfg.license, "License should be parsed")
-					assert.Equal(t, "test-license-id", installCfg.license.Spec.LicenseID)
-					assert.Equal(t, "test-app", installCfg.license.Spec.AppSlug)
+					assert.Equal(t, "test-license-id", installCfg.license.GetLicenseID())
+					assert.Equal(t, "test-app", installCfg.license.GetAppSlug())
 				} else {
 					assert.Empty(t, installCfg.licenseBytes, "License bytes should be empty")
 					assert.Nil(t, installCfg.license, "License should be nil")