feat: real range/bang/visual handling for the deferred command gaps

Implements the four items previously left as "needs handler work" — all
fully wired, not cosmetic.

- ToggleListItem / IncrementListItem / DecrementListItem are now -range
  (both clients). The client loops the per-line op over [<line1>,<line2>]
  (toggle_list_item_range / list_cycle_symbol_range). The server's edits are
  version-less single-line WorkspaceEdits, so each line applies independently
  — no server protocol change. `:'<,'>VimwikiToggleListItem` toggles the whole
  selection.
- VimwikiRebuildTags gains -bang: `:…RebuildTags!` passes { all: true } and
  the server (tags_rebuild) re-indexes every configured wiki via
  wikis_snapshot(), not just the current one.
- VimwikiNormalizeLink is -nargs=?: with `1` (upstream's visual flag; the
  x-mode `+` mapping now passes it) it wraps the '< / '> selection as
  [[selection]] (new wrap_visual_as_wikilink in both clients).
- VimwikiCheckLinks is -range: a ranged invocation filters the broken-link
  report to the current buffer's selected lines (client-side filter in
  results_to_qf / check_links).

Tests: cmd.toggle_list_item_range + cmd.normalize_link_visual_wraps_selection
(test-keymaps.lua), normalize.visual_wraps_selection (test-keymaps-vim.vim).
README + doc/nuwiki.txt + gap doc updated. fmt/clippy clean; nvim 274,
vim 266+18, all Rust tests + config-parity green.

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

lua/nuwiki/commands.lua

@@ -361,6 +361,27 @@ function M.cycle_list_item_back()
   exec('nuwiki.list.cycleCheckbox', a)
 end
 M.reject_list_item = _exec_pos('nuwiki.list.rejectCheckbox')
+
+-- Apply a per-line action across [l1, l2] (visual-range commands). Each call
+-- targets its own line; the server's version-less single-line edits apply
+-- independently as they return, so no conflict.
+local function over_range(l1, l2, fn)
+  local save = vim.api.nvim_win_get_cursor(0)
+  for ln = l1, l2 do
+    vim.api.nvim_win_set_cursor(0, { ln, 0 })
+    fn()
+  end
+  pcall(vim.api.nvim_win_set_cursor, 0, save)
+end
+
+function M.toggle_list_item_range(l1, l2)
+  over_range(l1, l2, M.toggle_list_item)
+end
+
+function M.list_cycle_symbol_range(direction, l1, l2)
+  over_range(l1, l2, function() M.list_cycle_symbol(direction) end)
+end
+
 M.heading_add_level = _exec_pos('nuwiki.heading.addLevel')
 M.heading_remove_level = _exec_pos('nuwiki.heading.removeLevel')
 
@@ -380,7 +401,11 @@ end
 M.toc_generate = function() exec('nuwiki.toc.generate', uri_args()) end
 M.links_generate = function() exec('nuwiki.links.generate', uri_args()) end
 
-function M.check_links()
+-- range>0 restricts the report to the current buffer's [l1, l2] lines
+-- (`:'<,'>VimwikiCheckLinks`); otherwise the whole workspace.
+function M.check_links(range, l1, l2)
+  local filter = type(range) == 'number' and range > 0
+  local cur = filter and vim.api.nvim_buf_get_name(0) or nil
   exec('nuwiki.workspace.checkLinks', uri_args(), function(r)
     if type(r) ~= 'table' or #r == 0 then
       vim.notify('nuwiki: no broken links')
@@ -388,12 +413,20 @@ function M.check_links()
     end
     local items = {}
     for _, b in ipairs(r) do
-      table.insert(items, {
-        filename = vim.uri_to_fname(b.uri),
-        lnum = (b.range and b.range.start and b.range.start.line or 0) + 1,
-        col = (b.range and b.range.start and b.range.start.character or 0) + 1,
-        text = (b.kind or '?') .. ': ' .. (b.message or ''),
-      })
+      local fname = vim.uri_to_fname(b.uri)
+      local lnum = (b.range and b.range.start and b.range.start.line or 0) + 1
+      if not filter or (fname == cur and lnum >= l1 and lnum <= l2) then
+        table.insert(items, {
+          filename = fname,
+          lnum = lnum,
+          col = (b.range and b.range.start and b.range.start.character or 0) + 1,
+          text = (b.kind or '?') .. ': ' .. (b.message or ''),
+        })
+      end
+    end
+    if #items == 0 then
+      vim.notify('nuwiki: no broken links')
+      return
     end
     vim.fn.setqflist({}, ' ', { title = 'nuwiki broken links', items = items })
     vim.cmd('copen')
@@ -451,10 +484,14 @@ function M.tags_generate_links(tag)
   exec('nuwiki.tags.generateLinks', { args })
 end
 
-function M.tags_rebuild()
-  exec('nuwiki.tags.rebuild', uri_args(), function(r)
+function M.tags_rebuild(all)
+  local a = uri_args()
+  a[1].all = all and true or false
+  exec('nuwiki.tags.rebuild', a, function(r)
     if r and r.pages then
-      vim.notify(string.format('nuwiki: re-indexed %d page(s)', r.pages))
+      local scope = (r.all and (r.wikis or 0) ~= 1)
+        and string.format(' across %d wikis', r.wikis or 0) or ''
+      vim.notify(string.format('nuwiki: re-indexed %d page(s)%s', r.pages, scope))
     end
   end)
 end
@@ -1027,11 +1064,25 @@ function M.paste_url()
   exec('nuwiki.link.pasteUrl', pos_args())
 end
 
---- Vimwiki `:VimwikiNormalizeLink` — wrap the word at cursor as
---- `[[word]]` without following. The `<CR>` two-step does the same
---- thing under the hood; expose it as a standalone command + keymap
---- for users who want to bind it to `+` per vimwiki defaults.
-function M.normalize_link()
+-- Wrap the single-line `'<`/`'>` visual selection as `[[selection]]`.
+local function wrap_visual_as_wikilink()
+  local sl, sc, el, ec = visual_selection_range()
+  if not (sl and sl == el) then return end
+  local line = vim.api.nvim_buf_get_lines(0, sl - 1, sl, false)[1] or ''
+  local sel = line:sub(sc + 1, ec + 1)
+  if sel == '' or sel:match('^%[%[.*%]%]$') then return end
+  local new = line:sub(1, sc) .. '[[' .. sel .. ']]' .. line:sub(ec + 2)
+  vim.api.nvim_buf_set_lines(0, sl - 1, sl, false, { new })
+end
+
+--- Vimwiki `:VimwikiNormalizeLink [1]` — wrap text as `[[…]]` without
+--- following. With `visual` (upstream's `1` arg / the `x`-mode `+` mapping)
+--- wrap the selection; otherwise the word at the cursor.
+function M.normalize_link(visual)
+  if visual then
+    wrap_visual_as_wikilink()
+    return
+  end
   if cursor_inside_wikilink() then return end
   wrap_cword_as_wikilink()
 end