feat(ST-qfpqpxzy): DB schema + settings-UI voor min_quota_pct worker-drempel (#118)

- User.min_quota_pct Int @default(20) + ClaudeWorker.last_quota_pct/last_quota_check_at
- Migratie add_worker_quota_gate
- lib/schemas/user.ts: minQuotaPctSchema (int, 1-100)
- actions/settings.ts: updateMinQuotaPctAction met auth/demo/zod-guard
- MinQuotaEditor component met numeric input en DemoTooltip
- Settings-pagina: Worker-instellingen sectie

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

app/(app)/settings/page.tsx

@@ -5,6 +5,7 @@ import { prisma } from '@/lib/prisma'
 import { RoleManager } from '@/components/settings/role-manager'
 import { LeaveProductButton } from '@/components/settings/leave-product-button'
 import { ProfileEditor } from '@/components/settings/profile-editor'
+import { MinQuotaEditor } from '@/components/settings/min-quota-editor'
 import { ActivateProductButton } from '@/components/shared/activate-product-button'
 import Link from 'next/link'
 
@@ -14,7 +15,7 @@ export default async function SettingsPage() {
   const [user, userRoles, ownedProducts, memberships] = await Promise.all([
     prisma.user.findUnique({
       where: { id: session.userId },
-      select: { username: true, email: true, bio: true, bio_detail: true, avatar_data: true, updated_at: true, active_product_id: true },
+      select: { username: true, email: true, bio: true, bio_detail: true, avatar_data: true, updated_at: true, active_product_id: true, min_quota_pct: true },
     }),
     prisma.userRole.findMany({ where: { user_id: session.userId } }),
     prisma.product.findMany({
@@ -157,6 +158,19 @@ export default async function SettingsPage() {
         )}
       </div>
 
+      <div className="bg-surface-container-low border border-border rounded-xl p-5 space-y-4">
+        <div>
+          <h2 className="text-sm font-medium text-foreground">Worker-instellingen</h2>
+          <p className="text-xs text-muted-foreground mt-0.5">
+            Drempelwaarden voor de Claude-worker.
+          </p>
+        </div>
+        <MinQuotaEditor
+          currentValue={user?.min_quota_pct ?? 20}
+          isDemo={session.isDemo ?? false}
+        />
+      </div>
+
       <div className="bg-surface-container-low border border-border rounded-xl p-5 space-y-3">
         <div className="flex items-center justify-between">
           <h2 className="text-sm font-medium text-foreground">API Tokens</h2>