add auto-review button that approves every high-confidence pending item

one-click for the common case: anything whose language came from
radarr/sonarr (confidence='high') is trusted enough to skip manual
review. low-confidence items stay pending.

- POST /api/review/auto-approve filters on rp.confidence='high' and
  enqueues audio jobs through the same dedup-guarded helper
- ColumnShell now takes actions[] instead of a single action, so the
  Review header can show Auto Review + Skip all side by side

src/features/pipeline/ProcessingColumn.tsx

@@ -51,7 +51,7 @@ export function ProcessingColumn({ items, progress, queueStatus, onMutate }: Pro
 		<ColumnShell
 			title="Processing"
 			count={job ? 1 : 0}
-			action={job ? { label: "Stop", onClick: stop, danger: true } : undefined}
+			actions={job ? [{ label: "Stop", onClick: stop, danger: true }] : undefined}
 		>
 			{queueStatus && queueStatus.status !== "running" && (
 				<div className="mb-2 text-xs text-gray-500 bg-white rounded border p-2">