Design streamlined GitHub issue-template set

### Description

Turn the approved hierarchy and audit findings into a concise template design. Define each template’s title prefix, labels, required fields, optional fields, default project behavior, and user-facing guidance.

### Action Items

- [ ] Draft the proposed template inventory and names.
- [ ] Define fields and validation for each agile work-item type.
- [ ] Preserve onboarding and offboarding as operational templates.
- [ ] Review the proposal with project leadership/product and capture approval.

### Additional Information

Parent Epic: https://github.com/hackforla/lucky-parking/issues/726

Start with the approved hierarchy and audit findings referenced in this issue, and review the parent epic at hackforla/lucky-parking#726 for context. Draft the template inventory, names, prefixes, labels, fields, project behavior, and guidance for each work-item type, including onboarding and offboarding. Done means project leadership/product has reviewed and approved the proposal.

Written by the indexing model from the issue text.