Match cooldown retry status messages

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/runtime-fallback/constants.ts

@@ -29,6 +29,7 @@ export const RETRYABLE_ERROR_PATTERNS = [
   /quota\s+will\s+reset\s+after/i,
   /all\s+credentials\s+for\s+model/i,
   /cool(?:ing)?\s+down/i,
+  /cooldown/i,
   /exhausted\s+your\s+capacity/i,
   /usage\s+limit\s+has\s+been\s+reached/i,
   /service.?unavailable/i,