Add missing :Nuwiki* aliases and drop dead deferred-stub code

Every :Vimwiki* command now has a canonical :Nuwiki* counterpart
(tables, colorize, clipboard paste, list-level/remove-done, and the
Neovim-only split/tab link-follow variants). Remove the now-unused
"not yet implemented" stub helpers (_not_yet, deferred,
s:notify_deferred) and the stale "deferred" comments, since every
command is implemented and server-backed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

lua/nuwiki/commands.lua

@@ -468,21 +468,6 @@ function M.rename_file()
   vim.lsp.buf.rename()
 end
 
--- ===== Deferred placeholders =====
---
--- These commands aren't implemented on the server yet. Stub them so the
--- `:Vimwiki*` compat surface exists and users get a clear message
--- instead of "unknown command".
-
-local function _not_yet(name)
-  return function()
-    vim.notify(
-      'nuwiki: ' .. name .. ' is not yet implemented',
-      vim.log.levels.WARN
-    )
-  end
-end
-
 -- Cluster A — list rewriters.
 
 -- `gl<Space>` — remove done items from the current list only. Passing the

lua/nuwiki/keymaps.lua

@@ -15,10 +15,6 @@
 --     text_objects  = true,  -- ah, ih, al, il
 --     wiki_prefix   = true,  -- <Leader>ww, <Leader>ws, <Leader>wi, …
 --   }
---
--- Mappings that point at deferred commands stub out to a
--- "not yet implemented" notification — better than a silent no-op
--- so users get parity *signalling*, not just parity in lhs.
 
 local M = {}
 
@@ -133,17 +129,6 @@ local function open_above_with_bullet()
   vim.api.nvim_feedkeys('O' .. prefix, 'n', false)
 end
 
--- ===== Stub for deferred commands =====
-
-local function deferred(name)
-  return function()
-    vim.notify(
-      'nuwiki: ' .. name .. ' is not yet implemented',
-      vim.log.levels.WARN
-    )
-  end
-end
-
 -- ===== Public attach =====
 
 function M.attach(bufnr, mappings)