Add Draft status option to task detail status dropdown

The status dropdown on task detail pages (/tasks/<id>) does not include Draft as an option. Users should be able to set a task to Draft status to prevent jr from working on it.

Fix location: Omni/Jr/Web.hs line 771

Current code:

statusDropdownOptions currentStatus tid =
  ...
    <| do
      statusOption TaskCore.Open currentStatus tid
      statusOption TaskCore.InProgress currentStatus tid
      statusOption TaskCore.Review currentStatus tid
      statusOption TaskCore.Approved currentStatus tid
      statusOption TaskCore.Done currentStatus tid

Fix: Add statusOption TaskCore.Draft currentStatus tid as the first option.

The statusOption helper already handles Draft styling (line 780), so no additional changes needed.