feat: update the permission for showing the usage of the user

src/app/api/usage/chart/route.js

@@ -1,10 +1,12 @@
 import { NextResponse } from "next/server";
 import { getChartData } from "@/lib/usageDb";
+import { requireUsageDashboardUser } from "@/lib/auth/currentUser";
 
 const VALID_PERIODS = new Set(["today", "24h", "7d", "30d", "60d"]);
 
 export async function GET(request) {
   try {
+    const user = await requireUsageDashboardUser();
     const { searchParams } = new URL(request.url);
     const period = searchParams.get("period") || "7d";
 
@@ -12,9 +14,10 @@ export async function GET(request) {
       return NextResponse.json({ error: "Invalid period" }, { status: 400 });
     }
 
-    const data = await getChartData(period);
+    const data = await getChartData(period, user);
     return NextResponse.json(data);
   } catch (error) {
+    if (error?.message === "Unauthorized") return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
     console.error("[API] Failed to get chart data:", error);
     return NextResponse.json({ error: "Failed to fetch chart data" }, { status: 500 });
   }