feat: company cascade delete + user management + settings focus fix + bulk delete components

- Company DELETE: cascade non-accounting deps (deals, projects, tickets, persons,
  leads, instances), block only on accounting (invoices, licenses, expenses,
  contracts) per GoBD rule. Transaction-wrapped.
- User management: GET /api/aos/users + PATCH role + DELETE (guards: no
  self-delete, no last owner delete, no env-admin delete).
- User management UI: table with inline role select, 2FA status, delete button.
- Settings focus fix: moved Field component outside render (was causing
  unmount/remount on each keystroke → focus loss).
- Bulk delete: useBulkSelect hook + BulkDeleteDialog + BulkActionBar.
- Cleaned all demo/mock data; re-bootstrapped admin account.

src/components/aos/crud/bulk-action-bar.tsx

@@ -0,0 +1,49 @@
+'use client'
+
+import { Trash2, X, CheckSquare } from 'lucide-react'
+import { Button } from '@/components/ui/button'
+import { cn } from '@/lib/utils'
+
+export function BulkActionBar({
+  count,
+  entityLabel,
+  onDelete,
+  onClear,
+  className,
+}: {
+  count: number
+  entityLabel: string
+  onDelete: () => void
+  onClear: () => void
+  className?: string
+}) {
+  if (count === 0) return null
+
+  return (
+    <div
+      className={cn(
+        'fixed bottom-4 left-1/2 z-50 flex -translate-x-1/2 items-center gap-3 rounded-lg border border-border bg-background px-4 py-2.5 shadow-lg',
+        className
+      )}
+    >
+      <span className="flex items-center gap-1.5 text-sm font-medium">
+        <CheckSquare className="size-4 text-muted-foreground" />
+        {count} {count === 1 ? entityLabel : `${entityLabel}e`} ausgewählt
+      </span>
+      <div className="h-4 w-px bg-border" />
+      <Button
+        size="sm"
+        variant="default"
+        className="gap-1.5 bg-foreground text-background hover:bg-foreground/90"
+        onClick={onDelete}
+      >
+        <Trash2 className="size-3.5" />
+        Ausgewählte löschen
+      </Button>
+      <Button size="sm" variant="ghost" className="gap-1" onClick={onClear}>
+        <X className="size-3.5" />
+        Auswahl aufheben
+      </Button>
+    </div>
+  )
+}