The form template iterated over changeset error tuples directly
(e.g. changeset.errors[:name] returns a tuple, not a list), causing
Protocol.UndefinedError for Enumerable on Tuple.
Rewrote form to use to_form/2 and <.input> components per LiveView
conventions. Errors are now handled properly by the input component.
- Index page with All/Active/Upcoming/Past filter tabs
- Show page with active banner, edit/delete actions
- Form page with scope picker (org-wide/site/device), datetime fields
- Nav link added to desktop and mobile nav