[air] Move AIR commands out of experimental

[caroline-db]

What did you change, and why?

• Move AIR commands and acceptance tests into their stable locations.
• Expose AIR through the top-level databricks air command and update command guidance accordingly.
• Keep databricks experimental air as a deprecated compatibility alias with replacement notices.
• Update ownership, help output, and release notes for the graduation.
• This change does not remove the deprecated alias, alter AIR command behavior or APIs, or address the pre-existing TestSubmitWorkload failure on main.

How do you know it works?

• Ran the AIR unit suite, excluding the pre-existing TestSubmitWorkload failure.
• Ran the experimental command unit suite.
• Ran the AIR and root-help acceptance suites.
• Verified the changed Go packages with golangci-lint.

[eng-dev-ecosystem-bot]

Integration test report

Commit: e9b485f

Run: 35178228406

	Env	🔄​flaky	✅​pass	🙈​skip	Time
🔄​	aws linux	2	274	32	8:33
✅​	aws windows		278	30	6:23
✅​	azure linux		275	32	4:03
🔄​	azure windows	1	276	30	7:01
✅​	gcp linux		276	32	4:18
✅​	gcp windows		278	30	5:40

	Test Name	aws linux	azure windows
🔄​	TestAccept	✅​p	🔄​f
🔄​	TestFsCpFileToDirWithOverwriteFlag/dbfs_to_uc-volumes	🔄​f	✅​p
🔄​	TestFsCpFileToDirWithOverwriteFlag/uc-volumes_to_uc-volumes	🔄​f	✅​p

Top 3 slowest tests (at least 2 minutes):

duration	env	testname
6:20	aws windows	TestAccept
5:38	gcp windows	TestAccept
3:19	azure windows	TestAccept