feat(13.1-B): table rewriters — insert, align, moveColumn

Closes the table-rewriter cluster from SPEC §13.1.

Server-side (ops module):
- `render_blank_table(cols, rows)` — pure templating: header row,
  separator `|--|--|--|`, then `rows` empty data rows. Wired through
  `table_insert` which dispatches a `TextEdit` at the cursor.
- `table_align_edit` — locates the `TableNode` containing the cursor
  line, computes max width per column across every row, re-emits the
  table with each cell space-padded to its column's width. The
  parser drops `|---|---|` separator rows but sets
  `TableNode.has_header`; the renderer re-inserts a padded separator
  after the header so the result still parses.
- `table_move_column_edit` — column-under-cursor swap with the
  left or right neighbour (`dir = "left" | "right"`). Cursor column
  is computed by counting pipe separators before the cursor's byte
  offset on the row's line. Column widths swap alongside the data so
  the post-swap table stays aligned. No-ops cleanly when the swap
  would fall off either edge.

Editor glue:
- `lua/nuwiki/commands.lua` / `autoload/nuwiki/commands.vim` — the
  three "not yet implemented" stubs are replaced with real LSP
  dispatchers. `table_insert` accepts optional `cols`/`rows`
  arguments (defaults: 3×2).
- Default keymaps `gqq` / `gq1` / `gww` / `gw1` now call
  `table_align`; `<A-Left>` / `<A-Right>` call
  `table_move_column_left` / `_right`. No more "deferred"
  notifications on the table keys.

Tests: 8 new in `cluster_b_table_rewriters.rs` — blank-table shape
(3×2 + 1×1), column-width alignment with separator-row repad, swap-
right shape, swap-left clamp at column 0, no-table-found fallbacks,
COMMANDS list completeness. Total 410 Rust tests pass; clippy clean;
Neovim keymap harness still 20/20.

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

lua/nuwiki/commands.lua

@@ -474,9 +474,33 @@ function M.list_change_lvl(direction)
   M.list_change_level(delta, false)
 end
 
-M.table_insert = _not_yet(':VimwikiTable')
-M.table_move_column_left = _not_yet(':VimwikiTableMoveColumnLeft')
-M.table_move_column_right = _not_yet(':VimwikiTableMoveColumnRight')
+-- §13.1 Cluster B — table rewriters.
+
+function M.table_insert(cols, rows)
+  cols = tonumber(cols) or 3
+  rows = tonumber(rows) or 2
+  local p = pos_args()[1]
+  p.cols = cols
+  p.rows = rows
+  exec('nuwiki.table.insert', { p })
+end
+
+function M.table_align()
+  exec('nuwiki.table.align', pos_args())
+end
+
+function M.table_move_column_left()
+  local p = pos_args()[1]
+  p.dir = 'left'
+  exec('nuwiki.table.moveColumn', { p })
+end
+
+function M.table_move_column_right()
+  local p = pos_args()[1]
+  p.dir = 'right'
+  exec('nuwiki.table.moveColumn', { p })
+end
+
 M.colorize = _not_yet(':VimwikiColorize')
 
 -- §13.1 Cluster C — link helpers.

lua/nuwiki/keymaps.lua

@@ -255,12 +255,12 @@ function M.attach(bufnr, mappings)
 
   -- ===== Tables =====
   if on('table_editing') then
-    map('n', 'gqq', deferred(':VimwikiTableAlignQ'),  { desc = 'nuwiki: table align (deferred)' }, bufnr)
-    map('n', 'gq1', deferred(':VimwikiTableAlignQ1'), { desc = 'nuwiki: table align row1 (deferred)' }, bufnr)
-    map('n', 'gww', deferred(':VimwikiTableAlignW'),  { desc = 'nuwiki: table align wide (deferred)' }, bufnr)
-    map('n', 'gw1', deferred(':VimwikiTableAlignW1'), { desc = 'nuwiki: table align row1 wide (deferred)' }, bufnr)
-    map('n', '<A-Left>',  deferred(':VimwikiTableMoveColumnLeft'),  { desc = 'nuwiki: table col left (deferred)' }, bufnr)
-    map('n', '<A-Right>', deferred(':VimwikiTableMoveColumnRight'), { desc = 'nuwiki: table col right (deferred)' }, bufnr)
+    map('n', 'gqq', cmd.table_align, { desc = 'nuwiki: align table' }, bufnr)
+    map('n', 'gq1', cmd.table_align, { desc = 'nuwiki: align table' }, bufnr)
+    map('n', 'gww', cmd.table_align, { desc = 'nuwiki: align table (wide)' }, bufnr)
+    map('n', 'gw1', cmd.table_align, { desc = 'nuwiki: align table (wide)' }, bufnr)
+    map('n', '<A-Left>',  cmd.table_move_column_left,  { desc = 'nuwiki: move column left' }, bufnr)
+    map('n', '<A-Right>', cmd.table_move_column_right, { desc = 'nuwiki: move column right' }, bufnr)
   end
 
   -- ===== HTML =====