UI enhancements for checklist interaction and item management

[robpitcher]

This issue outlines several UI improvements for checklist functionality:

• Checklist Overview Page:

  • Underline the checklist name on mouse hover to indicate it's clickable.

• Checklist Scope:

  • Underline the item name on mouse hover to indicate it's clickable.
  • Change the "new checklist" button to "delete checklist" when viewing a checklist. Clicking "delete checklist" should prompt for in-page confirmation (not a popup), and on confirmation, delete the checklist and redirect to the checklist overview page.

• Checklist Item Management:

  • When adding checklist items, the category field should be blank by default (not prepopulated with "Miscellaneous").
  • Remove the priority property entirely. Instead, display and use the category label/tag, which should be visible in the checklist view (like priority labels previously) and be clickable/editable from the checklist view (no need to drill down to the item). The category label should also be editable from the scope of an individual checklist item.
  • Deleting a checklist item should use an in-page confirmation (not a popup).

• Documentation Update:

  • Update Copilot instructions and README files to reflect these changes. Remove any outdated information, but do not add new README files.

Acceptance Criteria:

• All UI changes are implemented as described above.
• Category label fully replaces priority property and is editable from both checklist overview and item scope.
• All delete actions use in-page confirmation.
• Documentation is updated as required.