Problem

Once an issue is created there is no way to change it. The issue detail page has no Edit / Update button — neither the title nor the Markdown description can be modified after creation. Typos or missing information can only be fixed by closing the issue and creating a new one.

Proposed solution

• Add an Edit button on the issue detail page (visible to users allowed to modify the issue, e.g. author and repo owner).
• Allow editing both the title and the Markdown description.
• Reuse the same Markdown editor/preview used on issue creation so the rendered result can be checked before saving.
• Persist changes and re-render the description with the existing Markdown pipeline.

Acceptance criteria

• [ ] Issue detail page shows an Edit action for authorized users
• [ ] Title can be changed and is validated like on creation
• [ ] Description (Markdown) can be changed and renders correctly after saving
• [ ] Unauthorized users do not see / cannot use the edit action

Migrated from https://gitshark.ha1nz.de/repos/miggi/GitShark/issues/3 (original author: miggi, created 2026-07-09)