feat(ST-1109.7): add status select to PBI dialog

- New components/shared/pbi-status-select.tsx mirrors PrioritySelect:
  PBI_STATUS_LABELS (NL), PBI_STATUS_COLORS, PbiStatusSelect component
- Reuses existing --status-todo/blocked/done MD3 tokens
- PbiDialog: status state with sync-on-open; default 'ready' for create,
  pbi.status for edit; hidden input submits lowercase API value
- Priority + Status sit side-by-side in 2-col grid
- PbiDialogPbi.status is optional; pbi-list.tsx will populate in ST-1109.8

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

components/shared/pbi-status-select.tsx

@@ -0,0 +1,41 @@
+'use client'
+
+import { Select, SelectContent, SelectItem, SelectTrigger } from '@/components/ui/select'
+import { cn } from '@/lib/utils'
+import type { PbiStatusApi } from '@/lib/task-status'
+
+export const PBI_STATUS_LABELS: Record<PbiStatusApi, string> = {
+  ready: 'Klaar voor sprint',
+  blocked: 'Geblokkeerd',
+  done: 'Afgerond',
+}
+
+export const PBI_STATUS_COLORS: Record<PbiStatusApi, string> = {
+  ready: 'bg-status-todo/15 text-status-todo border-status-todo/30',
+  blocked: 'bg-status-blocked/15 text-status-blocked border-status-blocked/30',
+  done: 'bg-status-done/15 text-status-done border-status-done/30',
+}
+
+interface PbiStatusSelectProps {
+  value: PbiStatusApi
+  onChange: (value: PbiStatusApi) => void
+  className?: string
+}
+
+export function PbiStatusSelect({ value, onChange, className }: PbiStatusSelectProps) {
+  return (
+    <Select
+      value={value}
+      onValueChange={(v) => { if (v) onChange(v as PbiStatusApi) }}
+    >
+      <SelectTrigger className={cn('w-full', className)}>
+        {PBI_STATUS_LABELS[value] ?? value}
+      </SelectTrigger>
+      <SelectContent>
+        <SelectItem value="ready">Klaar voor sprint</SelectItem>
+        <SelectItem value="blocked">Geblokkeerd</SelectItem>
+        <SelectItem value="done">Afgerond</SelectItem>
+      </SelectContent>
+    </Select>
+  )
+}