fix(lists): VimwikiToggleRejectedListItem -range parity (P3)

Upstream's :VimwikiToggleRejectedListItem is -range and binds glx in
visual mode; nuwiki's four defs were bare, so a ranged invocation raised
E481 and acted cursor-only. Same -range class already fixed for
ToggleListItem/Increment/Decrement -- ToggleRejected was missed.

All four defs (Vim+Neovim x Vimwiki*/Nuwiki*) are now -range, routed
through a new reject_list_item_range(l1, l2) looping over_range in both
clients, mirroring toggle_list_item_range. Visual glx stays cursor-only,
consistent with its <C-Space>/gln/glp siblings.

Also logs the 2026-06-02 re-audit findings in development/vimwiki-gap.md:
RemoveDone lost -range (low pri); config gaps list_margin
semantics/markdown-default, diary_months, markdown_header_style,
diary_caption_level=-1; and the path_html/template_path default-location
divergences. Mappings audit came back clean.

Tests: cmd.reject_list_item_range (test-keymaps.lua),
cmd.VimwikiToggleRejectedListItem_accepts_range (test-keymaps-vim.vim).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lua/nuwiki/commands.lua

@@ -385,6 +385,10 @@ function M.list_cycle_symbol_range(direction, l1, l2)
   over_range(l1, l2, function() M.list_cycle_symbol(direction) end)
 end
 
+function M.reject_list_item_range(l1, l2)
+  over_range(l1, l2, M.reject_list_item)
+end
+
 M.heading_add_level = _exec_pos('nuwiki.heading.addLevel')
 M.heading_remove_level = _exec_pos('nuwiki.heading.removeLevel')