- Cap maximum cooldown for rate limit handling in account unavailability and single-model chat flows

- Dynamic custom model fetching for model selection

open-sse/config/errorConfig.js

@@ -38,6 +38,9 @@ export const BACKOFF_CONFIG = {
 // Default cooldown for transient/unknown errors
 export const TRANSIENT_COOLDOWN_MS = 30 * 1000;
 
+// Hard cap for provider-reported rate limit cooldown (e.g. codex resets_at can be 5-6h)
+export const MAX_RATE_LIMIT_COOLDOWN_MS = 30 * 60 * 1000;
+
 // Cooldown durations (ms)
 const COOLDOWN = {
   long: 2 * 60 * 1000,