feat(commands): ChangeSymbolTo -range, GenerateLinks path filter, NuwikiGenerateTags

Closes the three new command gaps from the 2026-05-31 re-audit (all real,
client-side, both clients × Vimwiki/Nuwiki):

- VimwikiChangeSymbolTo / ListChangeSymbolI / NuwikiChangeSymbol are now
  -range -nargs=1 via a new list_change_symbol_range(symbol,l1,l2) helper that
  loops over_range; was -nargs=1 only → E481 on a visual selection.
  ChangeSymbolInListTo/InList stay range-less.
  Bonus: the Neovim VimwikiChangeSymbolInListTo + NuwikiChangeSymbolInList defs
  passed whole_list=false, changing only the current item — corrected to true.

- VimwikiGenerateLinks / NuwikiGenerateLinks are now -nargs=?; with an arg the
  client dispatches the existing server command nuwiki.links.generateForPath
  ({path}) for real subtree-scoped link generation, else nuwiki.links.generate.
  Was bare → E488 on an arg.

- Added NuwikiGenerateTags (Vim + Neovim) mirroring VimwikiGenerateTags, with
  -nargs=? -complete=…tags — closes the :Vimwiki*↔:Nuwiki* alias asymmetry.

Tests: cmd.ChangeSymbolTo_range_sets_marker, cmd.GenerateLinks_accepts_optional_path,
cmd.NuwikiGenerateTags_exists (test-keymaps.lua, 283 pass) +
cmd.VimwikiChangeSymbolTo_accepts_range, cmd.VimwikiGenerateLinks_accepts_path,
cmd.NuwikiGenerateTags_exists (test-keymaps-vim.vim, 272/18/21). fmt clean.

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

development/tests/test-keymaps.lua

@@ -873,6 +873,39 @@ vim.defer_fn(function()
         .. vim.inspect(vim.api.nvim_buf_get_lines(0, 0, -1, false)))
     end
   end)
+  -- `:[range]VimwikiChangeSymbolTo {sym}` — now -range -nargs=1. A 1,3 range
+  -- must set every item's marker to the given symbol.
+  tobj_case('cmd.ChangeSymbolTo_range_sets_marker', function()
+    set_buf({ '- a', '- b', '- c' })
+    vim.cmd('1,3VimwikiChangeSymbolTo *')
+    local done = vim.wait(2000, function()
+      local l = vim.api.nvim_buf_get_lines(0, 0, -1, false)
+      for _, ln in ipairs(l) do
+        if not ln:match('^%*%s') then return false end
+      end
+      return true
+    end, 30)
+    if not done then
+      error('range change-symbol did not set all markers: '
+        .. vim.inspect(vim.api.nvim_buf_get_lines(0, 0, -1, false)))
+    end
+  end)
+  -- `:VimwikiGenerateLinks [rel_path]` — now -nargs=? (was bare; an arg raised
+  -- E488). Both forms must dispatch without a Vim-level command error.
+  tobj_case('cmd.GenerateLinks_accepts_optional_path', function()
+    set_buf({ '= page =' })
+    local ok1 = pcall(vim.cmd, 'VimwikiGenerateLinks')
+    local ok2 = pcall(vim.cmd, 'VimwikiGenerateLinks subdir')
+    if not (ok1 and ok2) then
+      error('GenerateLinks rejected an arg: ok1=' .. tostring(ok1) .. ' ok2=' .. tostring(ok2))
+    end
+  end)
+  -- :NuwikiGenerateTags alias must exist (parity with :VimwikiGenerateTags).
+  tobj_case('cmd.NuwikiGenerateTags_exists', function()
+    if vim.fn.exists(':NuwikiGenerateTags') ~= 2 then
+      error(':NuwikiGenerateTags not defined')
+    end
+  end)
   -- `:VimwikiNormalizeLink 1` (the arg is upstream's visual flag; the command
   -- is -nargs=? not -range, so no `'<,'>`) wraps the last visual selection.
   tobj_case('cmd.normalize_link_visual_wraps_selection', function()