[FEATURE]: Support for delay config

[mubaidr]

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Please add support for delay between API calls. Some providers limit API calls at a time, and when using subgents this limit is reached too quickly leading to error.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Implement exponential back-off when hitting rate limits #1712: Implement exponential back-off when hitting rate limits — same core problem of rate limits halting sessions, requests automatic retry/backoff
• [FEATURE]: Configure model concurrency #12019: [FEATURE]: Configure model concurrency — requests concurrency control to avoid hitting rate limits, especially with subagents
• [FEATURE]: Add automatic retry with backoff for Alibaba/DashScope rate limit errors #21140: [FEATURE]: Add automatic retry with backoff for Alibaba/DashScope rate limit errors — very similar request for delay/retry when providers rate limit
• [FEATURE]: Cooldown-aware runtime failover on rate limits and temporary provider failures #16867: [FEATURE]: Cooldown-aware runtime failover on rate limits and temporary provider failures — related request for handling rate limits gracefully

[mubaidr]

#12019