Add cost metrics to analytics dashboard

lib/queries.test.ts

@@ -0,0 +1,46 @@
+import { beforeEach, describe, expect, mock, test } from "bun:test";
+
+const queryMock = mock(async () => [
+  {
+    date: "2026-04-01 13:00:00",
+    calls: 1,
+    prompt_tokens: 10,
+    completion_tokens: 20,
+    cache_creation_tokens: 3,
+    cache_read_tokens: 4,
+    quota: 100,
+  },
+]);
+
+mock.module("./db", () => ({
+  query: queryMock,
+}));
+
+const { getTrends } = await import("./queries");
+
+describe("getTrends", () => {
+  beforeEach(() => {
+    queryMock.mockClear();
+  });
+
+  test("adds optional detail filters to the trend query", async () => {
+    await getTrends("day", 101, 201, { username: "alice" });
+    expect(queryMock.mock.calls[0][0]).toContain("username = $3");
+    expect(queryMock.mock.calls[0][1]).toEqual([101, 201, "alice"]);
+
+    await getTrends("day", 102, 202, { model: "gpt-4.1" });
+    expect(queryMock.mock.calls[1][0]).toContain("= $3");
+    expect(queryMock.mock.calls[1][1]).toEqual([102, 202, "gpt-4.1"]);
+
+    await getTrends("day", 103, 203, { channelId: 7 });
+    expect(queryMock.mock.calls[2][0]).toContain("channel_id = $3");
+    expect(queryMock.mock.calls[2][1]).toEqual([103, 203, 7]);
+  });
+
+  test("keeps the hour in hourly trend buckets", async () => {
+    const trends = await getTrends("hour", 104, 204);
+
+    expect(queryMock.mock.calls[0][0]).toContain("date_trunc('hour'");
+    expect(trends[0].date).toBe("2026-04-01 13:00");
+  });
+});