feat: harden analytics dashboard

lib/metrics.test.ts

@@ -0,0 +1,10 @@
+import { describe, expect, test } from "bun:test";
+import { QUOTA_UNITS_PER_USD, quotaToUsd } from "./metrics";
+
+describe("metric conversions", () => {
+  test("converts quota units to USD", () => {
+    expect(QUOTA_UNITS_PER_USD).toBe(500000);
+    expect(quotaToUsd(500000)).toBe(1);
+    expect(quotaToUsd(250000)).toBe(0.5);
+  });
+});