Fix ISO sign step: find ISO by glob instead of action output #135

Job	Run time
Verify action & container pins	7s
Validate YAML configs	8s
Test Count Drift Check	41s
Python Test & Lint	36s
Image Reference Consistency	3s
Supply Chain & SBOM Verification	30s
Shell Script Lint	5s
Security Regression Tests	44s
Dependency Vulnerability Audit	54s
Documentation Validation	3s
Go Build & Test (mcp-firewall)	37s
Go Build & Test (tool-firewall)	32s
Go Build & Test (gpu-integrity-watch)	34s
Go Build & Test (registry)	35s
Go Build & Test (policy-engine)	34s
Go Build & Test (airlock)	35s
Go Build & Test (runtime-attestor)	31s
Go Build & Test (integrity-monitor)	33s
Go Build & Test (incident-recorder)	36s
Release Branch Hardened Gate	-1s
	8m 57s

Provide feedback