Backoff and retry for bulk issue creation

Prompt I used to fix works for Codeberg; haven't verified for GitHub or GitLab: Update git-related skills (primarily Wayfinder, to-spec, to-tickets, and setup-matt-pocock-skills) that utilize git API for bulk issue creation programmatically. Those skills must handle throttling to avoid getting blocked. Exponential Backoff: If you receive a 429 error, stop sending requests and use an exponential backoff algorithm with jitter (randomness) before retrying. Respect the Retry-After Header: Always check the HTTP response headers for a Retry-After field, which indicates exactly how many seconds you must wait before the platform will accept your next request. Prompt results (LLM-generated and human reviewed): [issue-tracker-codeberg.md](https://github.com/user-attachments/files/30106959/issue-tracker-codeberg.md) [to-spec_SKILL.md](https://github.com/user-attachments/files/30106978/to-spec_SKILL.md) [to-tickets_SKILL.md](https://github.com/user-attachments/files/30106984/to-tickets_SKILL.md) [wayfinder_SKILL.md](https://github.com/user-attachments/files/30106990/wayfinder_SKILL.md)