9770dd3474
The image-modal tag kebab's rename dialog still showed a leftover stub
('Merging two tags into one lands in FC-2c') on a name collision, dead-ending
the operator. The merge machinery has existed for a while — the Tags view
already resolves rename collisions this way. Wire TagRenameDialog to it: on the
409 collision hint, show the same merge confirmation FandomSetDialog uses
(target name, image associations moved, alias kept) and POST /api/tags/<id>/merge
into the existing tag.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>