test: implement staging smoke #541

Job	Run time
Python 3.12	1m 26s
Validate vendored assets / Validate vendored third-party assets	41s
JavaScript dashboard	12s
Dashboard scenario snapshots	37s
Python 3.13	1m 18s
Template gates	1m 0s
Coverage	1m 26s
Python 3.11	1m 21s
Validate runtime lock / Validate hash-pinned runtime dependencies	38s
	8m 39s

Provide feedback