Operator-flagged (again) on the tag-merge picker: Enter on the dropdown re-opens
it instead of accepting the selection. I'd already patched this twice (fandom
picker + fandom set dialog) with copy-pasted capture-phase handlers, so DRY it.
New composable useAcceptOnEnter(accept): tracks the menu state and, on a
capture-phase Enter, lets Vuetify pick when the menu is open but calls accept()
(and blocks the re-open) when it's closed. Applied to every confirm-style picker:
- TagsView merge-into picker (the reported one)
- AliasPickerDialog
- PostSeriesMenu add-to-existing
- FandomPicker + FandomSetDialog (refactored off their bespoke handlers)
One behavior, one place to change it.
