Prune and fix CI 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.

develop test.yml green on 3 straight pushes. #4508 fixed the authz 401 (iepoch), a rate-limit 429 flake, and stalled cache restores. #4511 cut 2.1s quick-tier sleep and one retired-route guard. Rejected changes are measured in the report.