Function withRetry

Adapters exports - Model adapters (Claude, OpenAI, Gemini, Ollama) Split from index.ts for file size compliance (Issue #285)

withRetry<T>(
operation: () => Promise<T>,
options?: WithRetryOptions,
): Promise<Result<T, RetryExhaustedError>>
Executes an operation with retry logic using exponential backoff.
Type Parameters
- T
  The return type of the operation
Parameters
- operation: () => Promise<T>
  The async operation to execute
- options: WithRetryOptions = {}
  Retry options (config, isRetryable predicate, onRetry callback)
Returns Promise<Result<T, RetryExhaustedError>>
A Result containing either the operation result or a RetryExhaustedError
Example
```
const result = await withRetry(
  () => fetchData('/api/data'),
  { config: { maxRetries: 5 } }
);

if (result.ok) {
  console.log(result.value);
} else {
  console.error('All retries failed:', result.error);
}
```
- Defined in packages/nexus-agents/src/adapters/retry.ts:319