Fix glp backward cycle and gl<Space> current-list scope

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>

lua/nuwiki/commands.lua

@@ -323,6 +323,12 @@ end
 
 M.toggle_list_item = _exec_pos('nuwiki.list.toggleCheckbox')
 M.cycle_list_item = _exec_pos('nuwiki.list.cycleCheckbox')
+-- `glp` cycles backward — same command, `reverse = true` in the payload.
+function M.cycle_list_item_back()
+  local a = pos_args()
+  a[1].reverse = true
+  exec('nuwiki.list.cycleCheckbox', a)
+end
 M.reject_list_item = _exec_pos('nuwiki.list.rejectCheckbox')
 M.heading_add_level = _exec_pos('nuwiki.heading.addLevel')
 M.heading_remove_level = _exec_pos('nuwiki.heading.removeLevel')
@@ -479,7 +485,14 @@ end
 
 -- §13.1 Cluster A — list rewriters.
 
+-- `gl<Space>` — remove done items from the current list only. Passing the
+-- cursor position scopes the server to the contiguous list block under it.
 function M.list_remove_done()
+  exec('nuwiki.list.removeDone', pos_args())
+end
+
+-- `gL<Space>` — remove done items across the whole buffer (no position).
+function M.list_remove_done_all()
   exec('nuwiki.list.removeDone', uri_args())
 end
 

lua/nuwiki/keymaps.lua

@@ -218,8 +218,8 @@ function M.attach(bufnr, mappings)
     map('n', 'gnt',       cmd.next_task,        { desc = 'nuwiki: next unfinished task' }, bufnr)
     map('n', 'gln',       cmd.cycle_list_item,  { desc = 'nuwiki: increment checkbox' }, bufnr)
     map('x', 'gln',       cmd.cycle_list_item,  { desc = 'nuwiki: increment checkbox' }, bufnr)
-    map('n', 'glp',       cmd.cycle_list_item,  { desc = 'nuwiki: decrement checkbox' }, bufnr)
-    map('x', 'glp',       cmd.cycle_list_item,  { desc = 'nuwiki: decrement checkbox' }, bufnr)
+    map('n', 'glp',       cmd.cycle_list_item_back, { desc = 'nuwiki: decrement checkbox' }, bufnr)
+    map('x', 'glp',       cmd.cycle_list_item_back, { desc = 'nuwiki: decrement checkbox' }, bufnr)
     map('n', 'glx',       cmd.reject_list_item, { desc = 'nuwiki: reject checkbox' }, bufnr)
     map('x', 'glx',       cmd.reject_list_item, { desc = 'nuwiki: reject checkbox' }, bufnr)
     map('n', 'glh', function() cmd.list_change_level(-1, false) end,
@@ -235,8 +235,8 @@ function M.attach(bufnr, mappings)
     map('n', 'gLr', cmd.list_renumber_all,
         { desc = 'nuwiki: renumber all lists' }, bufnr)
     map('n', 'gl<Space>', cmd.list_remove_done,
-        { desc = 'nuwiki: remove done items' }, bufnr)
-    map('n', 'gL<Space>', cmd.list_remove_done,
+        { desc = 'nuwiki: remove done items (current list)' }, bufnr)
+    map('n', 'gL<Space>', cmd.list_remove_done_all,
         { desc = 'nuwiki: remove done items (whole doc)' }, bufnr)
     map('n', 'o',         open_below_with_bullet, { desc = 'nuwiki: open below + bullet' }, bufnr)
     map('n', 'O',         open_above_with_bullet, { desc = 'nuwiki: open above + bullet' }, bufnr)