air: add environment field to config validation

[caroline-db]

Changes

• Add the resolved run environment to AIR workspace config validation, including the environment version or base environment and inline dependencies.
• Share environment construction with Jobs submission so validation and submission use the same payload shape.

Why

• Depends on air: validate --dry-run against the workspace backend #6934, which adds workspace config validation and dry-run wiring.
• Environment-specific configuration should be validated before upload or submission.

Tests

• go test ./cmd/air ./libs/testserver
• go test ./acceptance -run 'TestAccept/air' -tail -test.v
• ./task checks
• Live-tested dry-run behavior with both valid and invalid configurations on current backend.
• Tested with lite swapped future backend changes

PR description drafted with Codex.

[eng-dev-ecosystem-bot]

Integration test report

Commit: 6f0cfab

Run: 37564737343

	Env	✅​pass	🙈​skip	Time
✅​	aws linux	276	16	5:29
✅​	aws windows	278	14	3:19
✅​	azure linux	275	16	5:48
✅​	azure windows	277	14	3:14
✅​	gcp linux	276	16	5:27
✅​	gcp windows	278	14	3:08

Top 6 slowest tests (at least 2 minutes):

duration	env	testname
4:10	azure linux	TestAccept
3:54	aws linux	TestAccept
3:51	gcp linux	TestAccept
3:17	aws windows	TestAccept
3:07	azure windows	TestAccept
3:06	gcp windows	TestAccept