feat(a2ui): align validation with v0.9 CheckRule spec (#97) #318

Job	Run time
Cockpit — secret-gated integration	1m 8s
Cockpit — build / test	1m 32s
Cockpit — build all examples	4m 54s
Cockpit — representative capability smoke	1m 16s
Website — e2e	2m 12s
Website — lint / build	1m 38s
Cockpit — deploy smoke dry-run	1m 9s
Cockpit — e2e	1m 51s
Library — lint / test / build	1m 26s
Chat Agent — smoke	1m 15s
Deploy → Vercel	7m 24s
Production smoke	4m 44s
	30m 29s

Provide feedback