- Replace Vim.map("...", "\"+...", ...) with custom Vim.defineAction
handlers calling navigator.clipboard directly. The library's "+"
register implementation doesn't reliably write on Firefox.
Limitation: only yy/Y/visual-y reach system clipboard; bare
y<motion> still uses vim's internal register.
- Flip dropdown modal: default NORMAL (j/k arrows), `/` or `i`
enters search. Listener moved to document capture phase so closed
dropdowns receive keydown on Firefox.