Tag::DeletionsController looked up the tag and its replacement with
find_by, so a missing id or a tag belonging to another family left
@tag nil. create then called @tag.replace_and_destroy!, raising
NoMethodError and returning a 500 instead of a 404.
Use find in set_tag and set_replacement_tag so an out-of-scope id
raises ActiveRecord::RecordNotFound, which is rendered as 404. The
replacement lookup keeps a presence guard so deleting without a
replacement still works. This mirrors Category::DeletionsController.
Fixes#2469
Co-authored-by: agentloop <agentloop@localhost>
* Add sync model
* Fresh fixtures for sync tests
* Sync tests overhaul
* Fix entry tests
* Complete remaining model test updates
* Update system tests
* Update demo data task
* Add system tests back to PR checks
* More simplifications, add empty family to fixtures for easier testing
* Move Transfer to Account namespace
* Fix partial resolution due to namespacing plurality
* Make category and tag controllers consistent with namespacing convention
* Update stale partial reference
