Problem:
A mapping that enters terminal-mode (`:FzfLua files` via `:startinsert`)
never reaches a composite-end: terminal-mode runs no "normal" CmdFrames.
The composite collects the entire terminal session (and more) into `lhs`.
E.g. if I have `<M-/>` mapped to open `:FzfLua files`, then interact
with fzf-lua UI, the emitted CmdAtom looks like:
<M-/>… => { type='mapping', lhs='<M-/><C-N><C-N><CR>', keys=nil }
Solution:
End the composite when terminal-mode is entered, which emits a more
meaningful and repeatable atom:
<M-/>… => { type='mapping', lhs='<M-/>', keys=nil }