test(c-messages): add aimock e2e (Task #4 pilot slice 1) #1200

Job	Run time
CI scope	11s
examples/chat — e2e	3m 32s
Cockpit — build / test	1m 53s
Cockpit — build all examples	5m 21s
Cockpit — deploy smoke dry-run	1m 6s
Cockpit — representative capability smoke	1m 16s
Library — lint / test / build	3m 37s
Website — e2e	2m 31s
PostHog — dashboards-as-code drift check	1m 23s
Website — lint / build	1m 45s
Cockpit — secret-gated integration	3s
Cockpit — e2e (cockpit-chat-messages-angular)	2m 18s
examples/chat — python smoke	1m 24s
Cockpit — e2e (cockpit-chat-tool-calls-angular)	1m 55s
Cockpit — e2e (cockpit-langgraph-streaming-angular)	2m 9s
Cockpit — e2e (cockpit-chat-interrupts-angular)	2m 9s
Cockpit — e2e (cockpit-chat-subagents-angular)	2m 9s
Cockpit — e2e	3s
Canonical demo → Vercel	-1s
Deploy → Vercel	-1s
Production smoke	0s
	34m 43s

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