Preview what each model tier resolves to per harness provider

One row per provider and tier: the built-in default, the MODEL_TIER_<PROVIDER>_<TIER> value stored in swarm config (if any), which layer wins, and the concrete model it resolves to against the current catalog (latest: aliases resolved with the same soak and auto-upgrade rules as claim time, without recording a resolution). Ignores per-worker MODEL_TIER_* overrides and per-task models.