chore: shrink demo assistant widget to 3x3

packages/db/migrations/seed.ts

@@ -645,7 +645,7 @@ const buildDemoWidgets = (appIds: string[]): DemoWidget[] => [
   { kind: "dockerContainers", width: 6, height: 2, needsIntegration: false },
   { kind: "weather", width: 2, height: 1, needsIntegration: false },
   // Row 12: assistant
-  { kind: "assistant", width: 8, height: 4, needsIntegration: false },
+  { kind: "assistant", width: 3, height: 3, needsIntegration: false },
 ];
 
 const seedDemoUserAsync = async (db: Database) => {