nwhitehouse gives tabular review proper column controls

Adds the actions a real user needs once a review crosses ~5 columns:

Backend:
- POST /tabular-review/:reviewId/reprocess-column { columnIndex }
  Wipes the column's cells back to status='pending', then creates a
  tabular_jobs run via the existing bug-007 worker pool. The worker's
  existing "skip done cells" filter naturally re-processes them. Refuses
  with 409 if a job is already in flight on this review (workers would
  race against the wipe).
- DELETE /tabular-review/:reviewId/columns/:columnIndex
  Drops the column from columns_config and deletes its tabular_cells
  rows. Returns the canonical updated columns_config.
- Both endpoints reuse the existing ensureReviewAccess + filter
  helpers - no new auth surface.

Frontend:
- TREditColumnMenu picks up onHide + onReprocess props. New "Hide
  column" and "Reprocess" quick-action buttons in the edit panel
  header. New "Reprocess this column after save" checkbox next to
  the Save button (Save & reprocess label when checked).
- TabularReviewView tracks hiddenColumnIndices in localStorage keyed
  by review id (per-(review, device)). visibleColumns is the filtered
  set passed to TRTable. Toolbar grows a compact "N hidden - Show all"
  button that restores in one click.
- Delete now opens an inline confirmation modal that names the column
  and counts cells about to be deleted, instead of being instant.
- Reprocess kicks off the existing pollJob loop so the run-button shows
  N/total live, same UX as a full generate.

API helpers added: reprocessTabularColumn, deleteTabularColumn.

No schema changes. tsc clean both sides; all 16 backend tests pass.

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

User feedback on the per-column ⋯ menu: clunky for managing many
columns at once. Adds a centralised manager that mirrors what
work___ does - a sliders-icon button next to + Add column that opens
a popover with:

- "N of M shown" header
- Show all / Hide all bulk actions
- Per-column row: eye toggle (show/hide), name, format pill (TEXT,
  DATE, YES_NO etc.), trash icon (opens the existing confirm-delete
  modal)
- Hidden columns render line-through + EyeOff icon for clarity

The per-column ⋯ menu's Hide / Reprocess / Save & reprocess affordances
stay - they're still useful for one-off actions. The new menu is the
"manage everything at once" surface.

Component: ColumnVisibilityMenu.tsx. Renders inside TRTable next to the
+ button. Visibility state is owned by TabularReviewView (localStorage-
backed); the new menu is a controlled view over props.

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

The sliders icon was inside the table header next to the + Add column
control - the user pointed out it's the wrong place. Moved into the main
toolbar, sitting just before the "+ Add Documents" / "+ Add Columns"
group, matching the layout pattern from work___.

- Removed ColumnVisibilityMenu render + its 5 props from TRTable.
- Removed the import from TRTable.
- Added the import + render in TabularReviewView's toolbar, with the
  same handlers wired (handleToggleColumnVisibility, handleShowAllColumns,
  handleHideAllColumns, handleDeleteColumn).
- TRTable's column-header row goes back to its original layout (just
  the + Add column button) - no behavioural change there.

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