feat(ai): dashboard chat widget with invoice import + budget indicator

src/admin/pages/Dashboard.tsx

@@ -22,6 +22,7 @@ import DashSessions from "../components/dashboard/DashSessions";
 import DashTodayPlan, {
   type TodayPlan,
 } from "../components/dashboard/DashTodayPlan";
+import DashAssistant from "../components/dashboard/DashAssistant";
 
 const API_BASE = "/api/admin";
 
@@ -236,6 +237,9 @@ export default function Dashboard() {
         </Typography>
       </Box>
 
+      {/* AI Assistant widget */}
+      {hasPermission("ai.use") && <DashAssistant />}
+
       {/* 2FA Required Banner */}
       {user?.require2FA && !user?.totpEnabled && (
         <Card