Scoping the lock to the MODEL rather than the connection is the right layer for a `400 "Model is unavailable"` — a multi-day upstream outage on one model should not darken the account. Good discipline on the two allowlist-adjacent changes: gating the `markAccountUnavailable` branch on `ruleScope === "model"` AND `status === 400` leaves every other status on its existing path, and deliberately not widening `FULL_TEXT_RULE_PROVIDERS` keeps the #10880 egress-bucketed 429 classification intact. Reading the cooldown from the rule instead of a literal at the call site is what makes it self-healing.
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Validated in one consolidated worktree cut from `release/v3.8.51`, boarded together with the rest of this batch — zero conflicts between them.
- `typecheck:core` clean; `check:changelog-integrity` OK
- complexity 2799 / baseline 3218 and cognitive-complexity 1265 / baseline 1437 — both under baseline
- 86 focused assertions green across the batch's 10 unit test files, plus 16/16 on the v1 plugin option schema and 16/16 on the v2 option tests
- `check-file-size` rebaselined for this batch's real growth (annotation `_rebaseline_2026_09_11_mergebatch_v3851_maxmad_opencode`, landed on #13141). `open-sse/utils/stream.ts` was deliberately left frozen: it is already 3115 > 3098 on the pure tip with zero contribution from this batch.
⚠️ base-red inherited: #12732 — `Docs Gates`, `Merge integrity`, `No new ESLint warnings`, `Unit Tests fast-path` and `Fast Quality Gates` all reproduce on the pure `release/v3.8.51` tip (provider count 356 vs the 358 the modules define, SKILL.md drift, and the `stream.ts` freeze above). None of them touch these diffs.
Thanks @maxmad64bis.
Makes the ProviderErrorRule `scope` field real at the persistence layer, exclusively for agentrouter (owner decision; every other provider keeps byte-identical behavior).
checkFallbackError now surfaces `ruleScope` behind the HONORS_RULE_LOCK_SCOPE_PROVIDERS allowlist, and the agentrouter 403 path consults the rules before the generic apikey-FORBIDDEN early-return. markAccountUnavailable honors scope "connection" with a temporary connection cooldown instead of a per-model lockout — guarded so a permanent state can never be downgraded to a transient retry loop — and combo now skips the exhausted account within the same request, which also stops force-reusing the just-cooled connection via allowRateLimitedConnection.
Documented in RESILIENCE_GUIDE §7 with the honest limits (disableCooling connections keep per-model behavior; the 6h model-access cooldown is clamped by mlSettings.maxCooldownMs, 30min by default; same-request skip needs targets carrying their own connectionId).
Closes#10334
agentrouter.org signals temporary quota exhaustion with HTTP 403/400 and a Chinese body (用户额度不足) instead of 429, so clients like Claude Code treat it as permanent and abort, and the fallback engine classified it as a generic apikey AUTH_ERROR.
New registry open-sse/config/upstreamStatusRestatement.ts restates those statuses to 429 with a synthetic Retry-After at a single hook in chatCore's providerFailure block (after parseUpstreamError), so classification, combo aggregation and the client response all see a retryable error. 无权访问模型 (permanently no model access) is veto-listed and never restated.
agentrouter classification rules are registered in providerErrorRules.ts and reach the real checkFallbackError path through resolveRuleMatchBody() with an exclusive FULL_TEXT_RULE_PROVIDERS allowlist — every other provider keeps its previous behavior byte-for-byte.
Known limitations tracked in #10334: the rules' scope field is informational (persistence applies per-model lockout for agentrouter), the 403-only model-access rule has no production path yet, and errors embedded in 200 SSE streams are not restated.
Refs #10334
