Clean up and fix test suites

Review all test suites, delete stale, superseeded, those that were one off to check feature flags or absence of something. Kill the most long running or flaky with unit tests that execute in milliseconds. Regroup between quick and full, Fix broken tests in CI - GitHub Actions - look at a few recent test runs and fix broken/flaky tests. Babysit CI/CD until the tests (test.yaml) pass.

PR #6879 merged (2c3107a3d), and its Jaah Deploy succeeded. The six recent red test.yml runs were all regressions already fixed on develop, and CI is green. The two NodeVault e2e specs got cheaper (A,B,A,B: 21.8/18.8→4.4/4.5s and 8.9/6.9→3.7/2.7s) and a task-detail-fit flake is fixed (1/20 red→40/40 green). The sweeps found nothing to delete or move between tiers. Memory: used mem-18424; proposed 0.