fix(parity): fifth-pass re-audit — VimwikiGoto nargs, autowriteall, table_auto_fmt

Closes the actionable fifth-pass findings (gap doc updated):

- VimwikiGoto / NuwikiGoto: -nargs=1 -> -nargs=* in all four defs. Was a
  real bug — `:VimwikiGoto` raised E471, `:VimwikiGoto My Page` raised E488,
  and the handler's empty-arg prompt fallback was unreachable. Both clients
  already prompt on empty, so -nargs=* (keeping -complete=pages) restores
  upstream behavior.

- autowriteall (upstream default ON): while a wiki buffer is current, mirror
  Vim's global 'autowriteall' (auto-save on page switch / :make), restoring
  the prior value on leave. Neovim via ftplugin.lua setup_autowriteall
  (BufEnter/BufLeave) gated by the `autowriteall` setup option; Vim via the
  NuwikiAutoWriteAll augroup gated by g:nuwiki_autowriteall.

- table_auto_fmt (upstream default ON): re-align the table under the cursor
  on InsertLeave. Both clients, gated by `table_auto_fmt` / g:nuwiki_table_auto_fmt,
  guarded on the cursor line containing `|` before the async table_align.

Also logged (no code): VimwikiRenameFile missing -nargs=? (subsumed by the
LSP-rename divergence), table_reduce_last_col, user_htmls, hl_headers/
hl_cb_checked, and a commentstring value-mismatch note. Mappings audit clean.

The Neovim harness disables table_auto_fmt in setup (its async re-align would
perturb the deterministic table-nav keystroke cases); its wiring is verified
on a throwaway scratch buffer instead. Docs (README + doc/nuwiki.txt) updated.
Tests: cmd.VimwikiGoto_accepts_multiword, config.autowriteall_applied,
config.table_auto_fmt_autocmd. Neovim 293, Vim 285/18/21 pass.

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

development/vimwiki-gap.md

@@ -172,6 +172,21 @@ fix site.
 ## P3 — Niche / low impact
 
 ### Commands
+- [x] **`VimwikiGoto`/`NuwikiGoto` were `-nargs=1`** _(new, 2026-06-03 re-audit;
+  fixed same day)_ — upstream is `-nargs=*` (`ftplugin/vimwiki.vim:337`); nuwiki's
+  four defs were `-nargs=1`, so `:VimwikiGoto` (no arg) raised **E471** and
+  `:VimwikiGoto My Page` (spaced name) raised **E488** — and the handler's
+  empty-arg `input('Goto page: ')` prompt fallback was unreachable. _Fix:_ all
+  four defs (Vim+Neovim × `Vimwiki*`/`Nuwiki*`) are now `-nargs=*` (keeping
+  `-complete=…pages`); `<q-args>` joins a spaced name and an empty arg reaches
+  the prompt. Both handlers already prompt on empty. Covered by
+  `cmd.VimwikiGoto_accepts_multiword` (`test-keymaps-vim.vim`).
+- [ ] **`VimwikiRenameFile` lacks `-nargs=?`** _(new, 2026-06-03 re-audit)_ —
+  upstream is `-nargs=? -complete=…file`; nuwiki's defs are bare, so
+  `:VimwikiRenameFile foo` raises E488. Subsumed by the existing "rename
+  delegates to the LSP rename request, takes no filename arg" divergence (the
+  `-complete=` item below) — adding `-nargs=?` (accepted-ignored) would restore
+  signature parity if desired. Low priority.
 - [ ] `VimwikiVar` — config-var get/set introspection. _Fix:_ `plugin/nuwiki.vim`.
 - [x] **`VimwikiShowVersion`** _(fixed 2026-06-03)_ — added global
   `VimwikiShowVersion`/`NuwikiShowVersion` (both clients) echoing
@@ -400,6 +415,42 @@ fix site.
   `cmd.VimwikiSplitLink_accepts_args` (`test-keymaps-vim.vim`, no E488).
 
 ### Config
+- [x] **`autowriteall`** _(new, 2026-06-03 re-audit; fixed same day)_ — upstream
+  global (`vars.vim:136`, default **`1`/ON**): while a wiki buffer is current,
+  mirror Vim's global `'autowriteall'` (auto-save a modified buffer on page
+  switch / `:make`), restoring the prior value on leave (upstream
+  `plugin/vimwiki.vim:165-166,39`). nuwiki had no equivalent → out-of-box
+  behavioral divergence. _Fix:_ client-side, both clients — Neovim
+  `lua/nuwiki/ftplugin.lua` (`setup_autowriteall`, BufEnter/BufLeave save+set/
+  restore) gated by the `autowriteall` setup option (default true); Vim
+  `ftplugin/vimwiki.vim` (`NuwikiAutoWriteAll` augroup) gated by
+  `g:nuwiki_autowriteall` (default 1). Covered by `config.autowriteall_applied`
+  in both harnesses.
+- [x] **`table_auto_fmt`** _(new, 2026-06-03 re-audit; fixed same day)_ —
+  upstream global (`vars.vim:183`, default **`1`/ON**): re-format the table under
+  the cursor on `InsertLeave` (upstream `plugin/vimwiki.vim:330`). nuwiki had no
+  equivalent (tables formatted only via `gqq`/`gww`). _Fix:_ client-side
+  `InsertLeave` autocmd, gated by config — Neovim `table_auto_fmt` setup option
+  (default true, `ftplugin.lua` `setup_table_auto_fmt`); Vim
+  `g:nuwiki_table_auto_fmt` (default 1, `NuwikiTableAutoFmt` augroup). Both guard
+  on the cursor line containing `|` before the (async LSP) `table_align`, so
+  non-table edits don't round-trip. Covered by `config.table_auto_fmt_autocmd`
+  in both harnesses. _(Divergence: nuwiki's `table_align` is an async server
+  edit, vs upstream's synchronous format — the result lands a beat after Esc.)_
+- [ ] **`table_reduce_last_col`** _(new, 2026-06-03 re-audit)_ — upstream global
+  (`vars.vim:184`, default `0`): don't expand the last column separator to fill
+  the cell. nuwiki absent. Low impact (off by default). _Fix:_ thread a flag into
+  the table-format routine.
+- [ ] **`user_htmls`** _(new, 2026-06-03 re-audit)_ — upstream global
+  (`vars.vim:191`, default `''`): comma-separated HTML files with no wiki source
+  that `:VimwikiAll2HTML` must not delete. nuwiki absent — only relevant if
+  nuwiki's all-to-HTML prunes orphan HTML (it may not, in which case this is moot
+  and worth a one-line divergence note rather than code).
+- [ ] **`hl_headers` / `hl_cb_checked`** _(new, 2026-06-03 re-audit)_ — upstream
+  globals (`vars.vim:158`/`157`, both default `0`): per-level header highlight /
+  checked-checkbox line highlight. nuwiki absent. Borderline — either implement
+  via highlight groups/semantic tokens, or fold into the `conceal*`/`maxhi`
+  highlighting-divergence family so future audits stop flagging them.
 - [x] **`list_margin` — buffer-side parity + markdown default** _(new,
   2026-06-02 re-audit; fixed 2026-06-02)_ — upstream (`vars.vim:516`, doc
   `vimwiki.txt:2667`): left-margin **width in spaces for buffer-side generated
@@ -449,7 +500,9 @@ fix site.
 - [ ] `dir_link` — index file to open when following a directory link.
 - [ ] `auto_chdir` — `:cd` into wiki root on open (client-side).
 - [ ] `bullet_types` / `cycle_bullets` — custom bullet glyphs + wrap-around.
-- [ ] `commentstring` (`'%%%s'`) — comment toggling/text-objects.
+- [ ] `commentstring` (`'%%%s'`) — comment toggling/text-objects. _(2026-06-03
+  re-audit: also a value mismatch — nuwiki hardcodes `%% %s` (with a space) in
+  `ftplugin/vimwiki.vim:18` vs upstream's no-space `%%%s`; align when picked up.)_
 - [ ] `color_tag_template` — `color_dic` present; template regex missing.
   Related divergence _(2026-05-31 config re-audit)_: nuwiki's `color_dic`
   defaults to **empty** while upstream ships a populated palette
@@ -608,3 +661,13 @@ audits don't re-flag them.
   of the documented "generated-content is vimwiki-only" divergence. All five
   P1-blocking sections remain clear; only niche P3 items (and the deferred
   markdown work) are left.
+- Re-audited 2026-06-03 (fifth pass — commands / config / mappings, three
+  parallel agents) against vimwiki `a54a300` (still no upstream commits since
+  2026-04-30). **Mappings: clean** again (confirmed `gLH/gLL/gLR` correct; no new
+  gaps, no regressions). **Commands:** one real bug — `VimwikiGoto`/`NuwikiGoto`
+  were `-nargs=1` (E471/E488 + unreachable prompt), fixed same day; plus
+  `VimwikiRenameFile`'s missing `-nargs=?` logged (subsumed by the LSP-rename
+  divergence). **Config:** five new items — `autowriteall` and `table_auto_fmt`
+  (both ON upstream → out-of-box divergences, implemented same day),
+  `table_reduce_last_col`, `user_htmls`, `hl_headers`/`hl_cb_checked` logged; and
+  a `commentstring` value-mismatch note. No previously-closed item regressed.