Clarify issue format: keep technical decisions and implementation plan in PR artifacts

[MariusStorhaug]

Issue descriptions should stay on the functionality/request side and avoid prescribing implementation approach. The agent's role at issue stage is to collect and clarify requests; the team decides solution design during planning and PR review.

Request

Update issue-format guidance so default issue bodies focus on user problem, functional outcomes, and acceptance criteria, while intentionally avoiding technical design decisions and implementation planning details.

Desired outcome

• Issue captures what is needed and why it matters
• Issue avoids how to implement
• Team and reviewers decide architecture/implementation in planning + PR artifacts
• Guidance explicitly discourages embedding solution design in issue bodies

References

• Example issue adjusted to functional-only framing: PSModule/Domeneshop#2
• Linked delivery PR artifact: PSModule/Domeneshop#16