The pool-fleet migration is complete: the control-plane harness plus the
prod workers (deployed 2026-06-19, HARNESS_ROLE=worker, pool count 2) now
cover every probe dimension the interim `harness-legacy` fleet-migration
bridge was holding live, so `harness-legacy` is dead config.
This is the code-side cleanup only:
- Remove the `harness-legacy` entry from the railway-envs SSOT and the
now-dead `key === "harness-legacy"` special-case in computePromoteClosure.
- Regenerate railway-envs.generated.json (41 -> 40 services).
- Drop harness-legacy from the golden snapshot, the gateIgnore expectation
sets, the promote-notify fixtures, and the redeploy-env doc comments;
update the service-count assertions (41 -> 40).
- Fix the stale "STAGING-ONLY" harness-workers comment: prod workers are
live on Railway, though this SSOT entry still models the staging
instance only (no prod env backfilled here yet).
The live Railway `harness-legacy` service is torn down separately as a
follow-up infra step.
Adds three canonical fixtures under showcase/test-fixtures/promote-notify/:
success.json (29 services green), partial.json (26 green / 3 red with
mixed exit codes + categories), and total-failure.json (29 red fleet
abort with truncation-suffix sentinel).
Includes validate.sh — strict schema enforcement (rc propagation, enum +
regex assertions for run_id, pre_staging, abort_reason, category, exit
codes). And a README documenting the fixture contract + how to dispatch
them via gh workflow run.