fix(tables): auto-realign on edit + stop dragging trailing | onto new row

Two bugs in the insert-mode table editing path:

1. <Tab> past the last cell (and <CR> on a table row) used <CR>+typed
   keystrokes to create a new row, which split the current line at the
   cursor — pulling the trailing | down onto the next line and mangling
   the formatting. Both paths now go through helpers that append() a
   fresh row beside the current one without touching it.

2. The table never realigned to new content. Ported the LSP-side
   render_aligned_table algorithm to Lua + VimL so smart_tab,
   smart_shift_tab, and smart_return tighten column widths locally on
   every navigation. No vim-lsp / nuwiki server roundtrip required.

Neovim side schedules the work via vim.schedule (textlock-safe);
plain Vim hands off via <Cmd>:call …<CR> to keep insert mode and
avoid the cmdline-mode flash.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

autoload/nuwiki/commands.vim

@@ -684,6 +684,170 @@ function! nuwiki#commands#paste_url() abort
   call s:exec('nuwiki.link.pasteUrl', l:args)
 endfunction
 
+" ===== Pure-VimL table alignment =====
+"
+" Mirrors `lua/nuwiki/commands.lua`'s `align_table_at` so plain Vim
+" buffers get the same "tighten columns as cells grow" behaviour the
+" Neovim path enjoys, without needing a vim-lsp roundtrip. Algorithm
+" matches `crates/nuwiki-lsp/src/commands.rs::ops::render_aligned_table`.
+
+function! s:is_table_row(line) abort
+  return a:line =~# '^\s*|.*|\s*$'
+endfunction
+
+function! s:table_cell_starts(line) abort
+  " 1-based byte positions of each `|`. Cursor lands one past pipe N at
+  " 1-based byte (starts[N] + 1) — that's the first space inside the
+  " cell the pipe opens.
+  let l:out = []
+  let l:pos = 0
+  while 1
+    let l:bar = stridx(a:line, '|', l:pos)
+    if l:bar < 0 | break | endif
+    call add(l:out, l:bar + 1)
+    let l:pos = l:bar + 1
+  endwhile
+  return l:out
+endfunction
+
+function! s:find_table_range(row) abort
+  let l:total = line('$')
+  let l:s = a:row
+  while l:s > 1 && s:is_table_row(getline(l:s - 1))
+    let l:s -= 1
+  endwhile
+  let l:e = a:row
+  while l:e < l:total && s:is_table_row(getline(l:e + 1))
+    let l:e += 1
+  endwhile
+  return [l:s, l:e]
+endfunction
+
+function! s:parse_table_row(line) abort
+  let l:indent = matchstr(a:line, '^\s*')
+  let l:body = strpart(a:line, len(l:indent))
+  let l:segments = []
+  let l:pos = 0
+  while 1
+    let l:bar = stridx(l:body, '|', l:pos)
+    if l:bar < 0
+      call add(l:segments, strpart(l:body, l:pos))
+      break
+    endif
+    call add(l:segments, strpart(l:body, l:pos, l:bar - l:pos))
+    let l:pos = l:bar + 1
+  endwhile
+  " Drop the empty piece before the opening `|` and the trailing piece
+  " after the closing `|`.
+  if len(l:segments) > 0 && l:segments[0] ==# ''
+    call remove(l:segments, 0)
+  endif
+  if len(l:segments) > 0 && l:segments[-1] =~# '^\s*$'
+    call remove(l:segments, -1)
+  endif
+  call map(l:segments, {_, c -> substitute(substitute(c, '^\s\+', '', ''), '\s\+$', '', '')})
+  return [l:indent, l:segments]
+endfunction
+
+function! s:is_sep_cell(s) abort
+  return a:s !=# '' && a:s =~# '^[-:[:space:]]\+$'
+endfunction
+
+function! s:is_sep_row(cells) abort
+  if empty(a:cells) | return 0 | endif
+  for l:c in a:cells
+    if !s:is_sep_cell(l:c) | return 0 | endif
+  endfor
+  return 1
+endfunction
+
+function! s:compute_widths(rows) abort
+  let l:max_cols = 0
+  for l:r in a:rows
+    if len(l:r.cells) > l:max_cols
+      let l:max_cols = len(l:r.cells)
+    endif
+  endfor
+  let l:widths = repeat([1], l:max_cols)
+  for l:r in a:rows
+    if !s:is_sep_row(l:r.cells)
+      let l:i = 0
+      for l:c in l:r.cells
+        let l:w = strchars(l:c)
+        if l:w > l:widths[l:i]
+          let l:widths[l:i] = l:w
+        endif
+        let l:i += 1
+      endfor
+    endif
+  endfor
+  return l:widths
+endfunction
+
+function! s:render_table_row(indent, cells, widths, all_sep) abort
+  let l:out = a:indent . '|'
+  let l:i = 0
+  for l:w in a:widths
+    if a:all_sep
+      let l:out .= repeat('-', l:w + 2)
+    else
+      let l:c = l:i < len(a:cells) ? a:cells[l:i] : ''
+      let l:pad = l:w - strchars(l:c)
+      if l:pad < 0 | let l:pad = 0 | endif
+      let l:out .= ' ' . l:c . repeat(' ', l:pad) . ' '
+    endif
+    let l:out .= '|'
+    let l:i += 1
+  endfor
+  return l:out
+endfunction
+
+function! s:align_table_at(row) abort
+  let [l:s, l:e] = s:find_table_range(a:row)
+  let l:rows = []
+  let l:i = l:s
+  while l:i <= l:e
+    let [l:indent, l:cells] = s:parse_table_row(getline(l:i))
+    call add(l:rows, { 'indent': l:indent, 'cells': l:cells })
+    let l:i += 1
+  endwhile
+  let l:widths = s:compute_widths(l:rows)
+  if empty(l:widths) | return | endif
+  let l:new_lines = []
+  for l:r in l:rows
+    call add(l:new_lines, s:render_table_row(l:r.indent, l:r.cells, l:widths, s:is_sep_row(l:r.cells)))
+  endfor
+  call setline(l:s, l:new_lines)
+endfunction
+
+" Public helpers invoked via `<Cmd>` from the `<expr>` mappings. We
+" can't mutate the buffer from inside the `<expr>` body (textlock), so
+" the mappings hand off here via `<Cmd>:call …<CR>`, which runs an Ex
+" command without leaving insert mode.
+
+function! nuwiki#commands#_table_insert_row_below(row, cursor_col) abort
+  call s:align_table_at(a:row)
+  let l:line = getline(a:row)
+  let l:indent = matchstr(l:line, '^\s*')
+  let l:starts = s:table_cell_starts(l:line)
+  let l:cells = max([len(l:starts) - 1, 1])
+  let l:new_row = l:indent . '|' . repeat('   |', l:cells)
+  call append(a:row, l:new_row)
+  call cursor(a:row + 1, a:cursor_col)
+endfunction
+
+function! nuwiki#commands#_table_jump_to_cell(row, target_idx) abort
+  call s:align_table_at(a:row)
+  let l:starts = s:table_cell_starts(getline(a:row))
+  if a:target_idx < 1 || a:target_idx >= len(l:starts)
+    return
+  endif
+  " `starts[N]` is the 1-based byte position of the N-th `|`. The first
+  " space inside the cell that pipe opens sits at byte `starts[N] + 1`
+  " (1-based), which is what `cursor()` wants.
+  call cursor(a:row, l:starts[a:target_idx - 1] + 1)
+endfunction
+
 " Smart <CR> for insert mode — vimwiki `:VimwikiReturn` parity.
 " Used as `inoremap <expr> <CR> nuwiki#commands#smart_return()`. The
 " returned string is fed into Vim's input stream after the function
@@ -691,13 +855,12 @@ endfunction
 function! nuwiki#commands#smart_return() abort
   let l:line = getline('.')
   " `<expr>` runs under textlock, so the function must be side-effect-
-  " free on the buffer. The returned string is fed into Vim's input
-  " stream after we unwind — we encode the table-row insertion as
-  " explicit keystrokes (matches lua/nuwiki/commands.lua).
+  " free on the buffer. Buffer-mutating branches return a `<Cmd>:call
+  " …<CR>` keystroke that hands off to a regular function.
   if l:line =~# '^\s*|.*|\s*$'
-    let l:n = max([len(split(l:line, '|', 1)) - 2, 1])
-    let l:new_row = '|' . repeat('   |', l:n)
-    return "\<CR>" . l:new_row . "\<Esc>0li"
+    let l:indent = matchstr(l:line, '^\s*')
+    let l:cursor_col = len(l:indent) + 2
+    return "\<Cmd>call nuwiki#commands#_table_insert_row_below(" . line('.') . ", " . l:cursor_col . ")\<CR>"
   endif
   let l:m = matchlist(l:line, '^\(\s*\)\([-*#]\)\s\(.*\)$')
   if empty(l:m)
@@ -730,21 +893,10 @@ endfunction
 " Insert-mode `<Tab>` / `<S-Tab>` table navigation — vimwiki parity.
 " Used as `<expr>` mappings so we can pass `<Tab>` / `<S-Tab>` through
 " verbatim when the cursor isn't on a table row.
-function! s:table_cell_starts(line) abort
-  let l:out = []
-  let l:pos = 0
-  while 1
-    let l:bar = stridx(a:line, '|', l:pos)
-    if l:bar < 0 | break | endif
-    call add(l:out, l:bar + 1)
-    let l:pos = l:bar + 1
-  endwhile
-  return l:out
-endfunction
 
 function! nuwiki#commands#smart_tab() abort
   let l:line = getline('.')
-  if l:line !~# '^\s*|.*|\s*$'
+  if !s:is_table_row(l:line)
     return "\<Tab>"
   endif
   let l:starts = s:table_cell_starts(l:line)
@@ -752,37 +904,43 @@ function! nuwiki#commands#smart_tab() abort
     return "\<Tab>"
   endif
   let l:col = col('.') - 1
-  for l:s in l:starts
-    if l:s > l:col + 1 && l:s < len(l:line)
-      return "\<Esc>" . (l:s + 1) . '|i'
-    endif
-  endfor
-  let l:n = len(l:starts) - 1
-  let l:new_row = '|' . repeat('   |', l:n)
-  return "\<CR>" . l:new_row . "\<Esc>0li"
-endfunction
-
-function! nuwiki#commands#smart_shift_tab() abort
-  let l:line = getline('.')
-  if l:line !~# '^\s*|.*|\s*$'
-    return "\<S-Tab>"
-  endif
-  let l:starts = s:table_cell_starts(l:line)
-  if len(l:starts) < 2
-    return "\<S-Tab>"
-  endif
-  let l:col = col('.') - 1
-  let l:current_idx = -1
-  let l:i = 0
+  let l:current_idx = 1
+  let l:i = 1
   for l:s in l:starts
     if l:s <= l:col + 1 | let l:current_idx = l:i | endif
     let l:i += 1
   endfor
-  if l:current_idx <= 0
+  let l:target_idx = l:current_idx + 1
+  if l:target_idx < len(l:starts)
+    return "\<Cmd>call nuwiki#commands#_table_jump_to_cell(" . line('.') . ", " . l:target_idx . ")\<CR>"
+  endif
+  " Past the final cell → add a fresh row below, cursor in its first cell.
+  let l:indent = matchstr(l:line, '^\s*')
+  let l:cursor_col = len(l:indent) + 2
+  return "\<Cmd>call nuwiki#commands#_table_insert_row_below(" . line('.') . ", " . l:cursor_col . ")\<CR>"
+endfunction
+
+function! nuwiki#commands#smart_shift_tab() abort
+  let l:line = getline('.')
+  if !s:is_table_row(l:line)
     return "\<S-Tab>"
   endif
-  let l:target = l:starts[l:current_idx - 1]
-  return "\<Esc>" . (l:target + 1) . '|i'
+  let l:starts = s:table_cell_starts(l:line)
+  if len(l:starts) < 2
+    return "\<S-Tab>"
+  endif
+  let l:col = col('.') - 1
+  let l:current_idx = 0
+  let l:i = 1
+  for l:s in l:starts
+    if l:s <= l:col + 1 | let l:current_idx = l:i | endif
+    let l:i += 1
+  endfor
+  if l:current_idx <= 1
+    return "\<S-Tab>"
+  endif
+  let l:target_idx = l:current_idx - 1
+  return "\<Cmd>call nuwiki#commands#_table_jump_to_cell(" . line('.') . ", " . l:target_idx . ")\<CR>"
 endfunction
 
 " `:VimwikiNormalizeLink` — wrap the word at cursor as `[[word]]`