AgentWire-Cue v1.5.9 Audit Fix

Summary

• Critical fix: owner-alert/cue.yaml set_context was silently setting context["key"] and context["value"] instead of context["last_notified_round"]. Dedup guard was completely non-functional. Now uses correct direct key-value structure.
• resilience.on_exhaust is now validated at loader time against declared state names.
• Examples with match: "*" now have inline comments documenting the intent.

Verification

• CUE test suite: 334 passed, 6 skipped.