fix(runtime-fallback): classify quota exhaustion as STOP not retryable

Remove quota exhaustion patterns from RETRYABLE_ERROR_PATTERNS:

- 'usage limit reached' patterns (lines 30, 32)

- 'insufficient credits' pattern (line 37)

- 'credit balance too low' pattern (line 38)

These errors indicate permanent quota exhaustion, not temporary

rate limits. They are already handled by classifyErrorType() which returns

'quota_exceeded', and isRetryableError() properly stops on these

unless there's an explicit auto-retry signal.

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

@@ -27,15 +27,11 @@ export const RETRYABLE_ERROR_PATTERNS = [
   /too.?many.?requests/i,
   /quota\s+will\s+reset\s+after/i,
   /quota.?exceeded/i,
-  /(?:you(?:'ve|\s+have)\s+)?reached\s+your\s+usage\s+limit/i,
   /exhausted\s+your\s+capacity/i,
-  /usage\s+limit\s+has\s+been\s+reached/i,
   /all\s+credentials\s+for\s+model/i,
   /cool(?:ing)?\s+down/i,
   /model.{0,20}?not.{0,10}?supported/i,
   /model_not_supported/i,
-  /insufficient.?(?:credits?|funds?|balance)/i,
-  /credit.*balance.*too.*low/i,
   /service.?unavailable/i,
   /overloaded/i,
   /temporarily.?unavailable/i,