Add telemetry data quality guardrails #1004

Job	Run time
Cockpit — representative capability smoke	1m 15s
Cockpit — deploy smoke dry-run	1m 10s
Cockpit — build / test	1m 41s
Library — lint / test / build	3m 17s
Website — lint / build	1m 55s
Cockpit — build all examples	5m 3s
examples/chat — e2e	2m 24s
examples/chat — python smoke	1m 30s
Cockpit — secret-gated integration	1m 9s
Website — e2e	2m 26s
Cockpit — e2e	3m 4s
PostHog — dashboards-as-code drift check	1m 11s
Deploy → Vercel	0s
Production smoke	0s
	26m 5s

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