[maxmad64bis]

⚠️ base-red inherited: #13866

Summary

When the upstream reports a model as unavailable with a 400, the catalog rule now pins that outcome at registry level with a model-scoped lock and a bounded cooldown. Any other 400 from the same provider stays terminal and locks nothing. This is a catalog default only; the same effect was already reachable per install through settings.providerErrorRules.

Related Issues

• Related to fix(providers): reject incompatible ChatGPT Web Codex requests without account cooldown #12777 (a similar 400 on another provider, no rule proposed there).

Validation

• Change type: provider
• Focused tests and category gates from the golden path
• npm run lint — ESLint on the touched test file is clean; the full run is red on the base (🔴 Release branch not green: release/v3.8.51 #13866), unrelated to this diff
• Reconciled with the current active release base; focused checks rerun afterward
• Production-code changes include a new or updated automated test in this PR

Tests Added Or Updated

• tests/unit/opencode-400-model-unavailable-registry.test.ts (new, 3 cases: marked 400 locks the model, unmarked 400 stays terminal, cooldown comes from the rule; RED shown by local marker neutralization, restored byte-identical)
• Neighbors re-run green (5/5 + 9/9 on the two adjacent registry suites)

Coverage Notes

• Test-only change: no production file touched (git diff upstream/release/v3.8.51 -- open-sse/ is empty).
• No coverage movement.

Reviewer Notes

• The rule itself shipped earlier via fix(providers): lock opencode model on upstream 400 model-unavailable #13146; this PR pins it with a direct registry-level test so a future edit cannot silently widen or drop it. HONORS_RULE_LOCK_SCOPE_PROVIDERS already includes the provider, so no allowlist change is needed.
• Open PR fix(ops): egress-IP lockout provider allowlist override #13003 touches the same file on a disjoint hunk (EGRESS_OVERRIDE vs HONORS); rebase watch noted, no conflict at this base, and the inherited set matches feat(db): add per-proxy egress IP lookup by host and port #14250 (identical comparison with third-party fix(translator): parse DeepSeek Web DSML tool calls #14249, comm empty).
• CI reds are inherited from the red base (🔴 Release branch not green: release/v3.8.51 #13866), not from this diff: the third-party PR fix(sse): treat antigravity empty completions with a normal stop as valid 200s (#14160) #14243 on the same base release/v3.8.51 fails the same 9 jobs (API Route Typecheck, Docs Gates, Fast Quality Gates, Merge integrity, ESLint, Unit fast-path 1-4/4); every file cited by the failing gates is outside this diff. Non-blocking for this PR.