perf: memo GridCard, fuse save fns, fix slash tab active color

memento-note/app/api/user/ai-status/route.ts

@@ -0,0 +1,39 @@
+import { NextResponse } from 'next/server';
+import { auth } from '@/auth';
+import { getSystemConfig } from '@/lib/config';
+import { getAnyActiveByokForUser } from '@/lib/byok';
+import { resolveAiRoute } from '@/lib/ai/router';
+
+/**
+ * GET /api/user/ai-status
+ * Returns the effective AI provider and model for the current user.
+ * Used by the UI to show which model is active (BYOK vs admin).
+ */
+export async function GET() {
+  const session = await auth();
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const config = await getSystemConfig();
+  const adminRoute = resolveAiRoute('chat', config);
+
+  const byok = await getAnyActiveByokForUser(session.user.id, adminRoute.providerType);
+
+  if (byok) {
+    const model = (byok.model && byok.model.trim()) ? byok.model : adminRoute.modelName;
+    return NextResponse.json({
+      usedByok: true,
+      provider: byok.provider,
+      model,
+      source: 'byok',
+    });
+  }
+
+  return NextResponse.json({
+    usedByok: false,
+    provider: adminRoute.providerType,
+    model: adminRoute.modelName,
+    source: 'admin',
+  });
+}