feat(parity): P3 quick-wins — ShowVersion, gLH/gLL/gLR, Search/Align nargs

Closes four low-risk P3 parity items (gap doc updated):

- VimwikiShowVersion / NuwikiShowVersion: new global command (both clients)
  echoing g:nuwiki_version (0.1.0) + the host editor, via
  nuwiki#commands#show_version / commands.show_version.

- gLH / gLL / gLR: upstream's case-variant aliases of gLh/gLl/gLr (dedent /
  indent whole item, renumber all lists) added in both clients.

- VimwikiSearch / VWS: -nargs=1 -> -nargs=* (Vim + Neovim), so a multi-word
  search no longer raises E488 and an empty invocation reuses the last search
  pattern. (The lvimgrep-vs-vimwiki-engine difference stays open.)

- VimwikiTableAlignQ / AlignW / NuwikiTableAlign: bare -> -nargs=?, so
  `:VimwikiTableAlignQ 2` no longer raises E488 (optional column arg is
  accepted-and-ignored; the gqq-align vs gww-align-without-resize split
  stays open).

Docs (doc/nuwiki.txt + README) updated for the command and the aliases.
Tests: surface.{Vimwiki,Nuwiki}ShowVersion, map[n].gL{H,L,R} (both
harnesses), cmd.search_and_tablealign_nargs (vim). Neovim 291, Vim
282/18/21 pass.

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

README.md

@@ -253,7 +253,7 @@ require('nuwiki').setup({
     enabled       = true,
     wiki_prefix   = true,  -- <Leader>w{w,t,s,i}, <Leader>w<Leader>{w,y,t,m,i}
     links         = true,  -- <CR>, <S-CR>, <C-CR>, <C-S-CR>, <D-CR>, <M-CR>, <BS>, <Tab>, <S-Tab>, + (n/x), <Leader>w{n,d,r}, <Leader>wc (n/x)
-    lists         = true,  -- <C-Space>, gnt, gln, glp, glx, glh, gll, gLh, gLl, glr, gLr, gl{-,*,#,1,i,I,a,A}, gL{…}, gl, gL, o, O; insert <C-D>, <C-T>, <C-L><C-J/K/M>, <CR>
+    lists         = true,  -- <C-Space>, gnt, gln, glp, glx, glh, gll, gLh, gLl (aliases gLH/gLL), glr, gLr (alias gLR), gl{-,*,#,1,i,I,a,A}, gL{…}, gl, gL, o, O; insert <C-D>, <C-T>, <C-L><C-J/K/M>, <CR>
     headers       = true,  -- =, -, ]], [[, ]=, [=, ]u, [u
     table_editing = true,  -- gqq, gq1, gww, gw1, <A-Left>, <A-Right>; insert <Tab>, <S-Tab>
     diary         = true,  -- <C-Down>, <C-Up>
@@ -315,7 +315,7 @@ The `<Leader>w` prefix in the `wiki_prefix`, `links`, and `html_export` rows is
 | `enabled` | `true` | master switch for the whole keymap layer |
 | `wiki_prefix` | `true` | `<Leader>ww`, `<Leader>wt`, `<Leader>ws`, `<Leader>wi`, `<Leader>w<Leader>w`, `<Leader>w<Leader>y`, `<Leader>w<Leader>t`, `<Leader>w<Leader>m`, `<Leader>w<Leader>i` |
 | `links` | `true` | `<CR>`, `<S-CR>`, `<C-CR>`, `<C-S-CR>`, `<D-CR>`, `<M-CR>`, `<BS>`, `<Tab>`, `<S-Tab>`, `+` (normal + visual), `<Leader>wn`, `<Leader>wd`, `<Leader>wr`, `<Leader>wc` (normal + visual) |
-| `lists` | `true` | `<C-Space>` (also `<C-@>`/`<Nul>`), `gnt`, `gln`, `glp`, `glx`, `glh`, `gll`, `gLh`, `gLl`, `glr`, `gLr`, `gl-`, `gl*`, `gl#`, `gl1`, `gli`, `glI`, `gla`, `glA`, `gL-`, `gL*`, `gL#`, `gL1`, `gLi`, `gLI`, `gLa`, `gLA`, `gl`, `gL`, `o`, `O`; insert: `<C-D>`, `<C-T>`, `<C-L><C-J>`, `<C-L><C-K>`, `<C-L><C-M>`, `<CR>` |
+| `lists` | `true` | `<C-Space>` (also `<C-@>`/`<Nul>`), `gnt`, `gln`, `glp`, `glx`, `glh`, `gll`, `gLh`, `gLl`, `gLH`, `gLL`, `glr`, `gLr`, `gLR`, `gl-`, `gl*`, `gl#`, `gl1`, `gli`, `glI`, `gla`, `glA`, `gL-`, `gL*`, `gL#`, `gL1`, `gLi`, `gLI`, `gLa`, `gLA`, `gl`, `gL`, `o`, `O`; insert: `<C-D>`, `<C-T>`, `<C-L><C-J>`, `<C-L><C-K>`, `<C-L><C-M>`, `<CR>` |
 | `headers` | `true` | `=`, `-`, `]]`, `[[`, `]=`, `[=`, `]u`, `[u` |
 | `table_editing` | `true` | `gqq`, `gq1`, `gww`, `gw1`, `<A-Left>`, `<A-Right>`; insert: `<Tab>`, `<S-Tab>` |
 | `diary` | `true` | `<C-Down>`, `<C-Up>` |
@@ -388,7 +388,7 @@ For users configuring without Lua.
 | `g:nuwiki_no_default_mappings` | `0` | `1` skips the whole keymap layer |
 | `g:nuwiki_no_wiki_prefix_mappings` | `0` | `1` skips the `wiki_prefix` group (`<Leader>ww`, `<Leader>wt`, `<Leader>ws`, `<Leader>wi`, `<Leader>w<Leader>{w,y,t,m,i}`) |
 | `g:nuwiki_no_links_mappings` | `0` | `1` skips the `links` group (`<CR>`, `<S-CR>`, `<C-CR>`, `<C-S-CR>`, `<D-CR>`, `<M-CR>`, `<BS>`, `<Tab>`, `<S-Tab>`, `+`, `<Leader>w{n,d,r,c}`) |
-| `g:nuwiki_no_lists_mappings` | `0` | `1` skips the `lists` group (`<C-Space>`, `gnt`, `gln`, `glp`, `glx`, `glh`, `gll`, `gLh`, `gLl`, `glr`, `gLr`, `gl{-,*,#,1,i,I,a,A}`, `gL{…}`, `gl`, `gL`, `o`, `O`; insert `<C-D>`, `<C-T>`, `<C-L><C-J/K/M>`, `<CR>`) |
+| `g:nuwiki_no_lists_mappings` | `0` | `1` skips the `lists` group (`<C-Space>`, `gnt`, `gln`, `glp`, `glx`, `glh`, `gll`, `gLh`, `gLl` (aliases `gLH`/`gLL`), `glr`, `gLr` (alias `gLR`), `gl{-,*,#,1,i,I,a,A}`, `gL{…}`, `gl`, `gL`, `o`, `O`; insert `<C-D>`, `<C-T>`, `<C-L><C-J/K/M>`, `<CR>`) |
 | `g:nuwiki_no_headers_mappings` | `0` | `1` skips the `headers` group (`=`, `-`, `]]`, `[[`, `]=`, `[=`, `]u`, `[u`) |
 | `g:nuwiki_no_table_editing_mappings` | `0` | `1` skips the `table_editing` group (`gqq`, `gq1`, `gww`, `gw1`, `<A-Left>`, `<A-Right>`; insert `<Tab>`, `<S-Tab>`) |
 | `g:nuwiki_no_diary_mappings` | `0` | `1` skips the `diary` nav group (`<C-Down>`, `<C-Up>`) |