getExplicitModelOutputCap() (the clamp ceiling used by
resolveReasoningBufferedMaxTokens) only ever read the unvalidated synced
limit_output / registry / static-spec chain — it ignored the operator-settable
max_token capability override that getResolvedModelCapabilities() already
consulted. When a provider's synced catalog row reports a wrong limit_output
(e.g. ollama-cloud/deepseek-v4-flash: limit_output=1048576, same as
limit_context, while the real upstream cap is 65536), the reasoning-buffer
clamp trusted the bad number and inflated max_tokens 64000 -> 96000, which
upstream rejected with "exceeds model's maximum output tokens (65536)".
The override table (model_capability_overrides, "max_token" key,
/api/model-capability-overrides) is the existing, already-shipped remediation
path for exactly this class of bad catalog data, but reasoningTokenBuffer.ts
had no way to benefit from it. Extracted the override lookup into a shared
getMaxTokenCapabilityOverride() helper and made getExplicitModelOutputCap()
consult it first, so both read paths now agree.
