The right-arrow help never worked for subcommand completions and rendered into
the bottom toolbar (unreadable). Rework it to present in the completion dropdown
— the same two-column form as normal completions — and fix the surrounding
keyboard interactions, all verified by driving the real app through a terminal
emulator (not just unit tests).
- Help now renders as dropdown rows (hints.help_rows), never the bottom bar. The
completer yields the target command's name/usage/options/notes as non-inserting
Completion("") rows while help is open; the bottom bar keeps only the one-line
hint.
- resolve_target: strip the trailing space subcommand completions carry, and don't
re-append a token the menu already inserted into the buffer — both silently made
the panel resolve to nothing.
- RIGHT captures the highlighted node + buffer/complete_state; LEFT restores the
EXACT pre-RIGHT selection. Detach the menu with complete_state=None rather than
cancel_completion(), which calls go_to_completion(None) and wipes the highlighted
index (this is what made Tab commit the wrong command after a RIGHT/LEFT trip).
- Rebind backspace/delete/C-w/C-u to re-run completion: complete_while_typing only
fires on insert, so deleting characters left the dropdown stale/blank.
Tests updated to the real live states (trailing-space completions, post-insertion
buffer), plus guards pinning the detach-not-cancel invariant and the delete-key
rebinding.
d0339bceb5