Two documented checkbox-list mappings did not match their spec:
- `glp` dispatched the same forward-only cycleCheckbox as `gln`, so it
could never "cycle the checkbox state backward". Add `ops::cycle_state_back`
and thread a `reverse` flag through the dispatcher and both clients.
- `gl<Space>` and `gL<Space>` both swept the whole buffer, making them
identical. `gl<Space>` now passes the cursor position and the server
scopes deletion to the contiguous list block under the cursor (current
list, cascading into sublists); `gL<Space>` stays whole-buffer.
Adds Rust unit tests, plus behavioral and full-registration coverage for
the documented mapping surface in the Neovim and Vim keymap harnesses, and
a command-coverage suite mirroring the doc's command groups.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
