fix(client): VimwikiColorize accepts a range (no more E481 on selection)

Selecting text and running :VimwikiColorize {color} raised
"E481: No range allowed" — Vim prepends '<,'> to the command when invoked
from a visual selection, but the command was defined without -range.

All four colorize command defs (Vim + Neovim, Vimwiki* + Nuwiki*) are now
-range and forward the range count to the handler. A ranged (visual)
invocation wraps the '< / '> selection; a bare invocation wraps the cword.
The x-mode <Leader>wc mapping passes the visual flag explicitly.

The Vim-branch colorize() gained selection support (it was cword-only),
matching the Neovim branch, so both clients wrap a visual selection
identically. visual_selection_range() (Lua) no longer gates on
vim.fn.visualmode() — the explicit visual flag now carries that intent, and
the marks check guards unset selections.

Tests: cmd.Colorize_range_wraps_selection (nvim) and
colorize.{command_wraps_cword,visual_wraps_selection,ranged_command_no_error}
(vim). nvim 268, vim 257+18, all green.

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

autoload/nuwiki/commands.vim

@@ -855,10 +855,14 @@ function! nuwiki#commands#table_move_right() abort
         \ }]
   call s:exec('nuwiki.table.moveColumn', l:args)
 endfunction
-" `:VimwikiColorize {color}` — pure-VimL wrap as inline span tag,
-" matching vimwiki's `<span style="color:%c">%s</span>` template.
+" `:VimwikiColorize {color}` — wrap text in an inline colour span, matching
+" vimwiki's `<span style="color:%c">%s</span>` template. Wraps the visual
+" selection when invoked with a range (`:'<,'>VimwikiColorize` / the `x`-mode
+" <Leader>wc mapping), otherwise the word under the cursor.
+"   a:1 = colour (empty → prompt); a:2 = range count (>0 → use the selection).
 function! nuwiki#commands#colorize(...) abort
   let l:color = a:0 >= 1 ? a:1 : ''
+  let l:visual = a:0 >= 2 && a:2 > 0
   if l:color ==# ''
     let l:color = input('Colour: ')
   endif
@@ -867,6 +871,28 @@ function! nuwiki#commands#colorize(...) abort
   endif
   let l:open_tag = '<span style="color:' . l:color . '">'
   let l:close_tag = '</span>'
+
+  if l:visual
+    let l:sp = getpos("'<")
+    let l:ep = getpos("'>")
+    if l:sp[1] > 0 && l:sp[1] == l:ep[1]
+      let l:line = getline(l:sp[1])
+      let l:sc = l:sp[2]
+      let l:ec = l:ep[2]
+      if l:ec > strlen(l:line)
+        let l:ec = strlen(l:line)
+      endif
+      if l:ec >= l:sc
+        let l:new = strpart(l:line, 0, l:sc - 1)
+              \ . l:open_tag . strpart(l:line, l:sc - 1, l:ec - l:sc + 1) . l:close_tag
+              \ . strpart(l:line, l:ec)
+        call setline(l:sp[1], l:new)
+        return
+      endif
+    endif
+    " Multi-line or empty selection: fall through to the cword.
+  endif
+
   let l:line = getline('.')
   let l:col = col('.')
   " Word boundaries around cursor (1-based).