feat(health): report build version

apps/web/src/app/healthz/route.test.ts

@@ -1,12 +1,22 @@
-import { describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import { GET } from "./route";
 
 describe("health endpoint", () => {
-  it("reports process readiness without requiring external services", async () => {
+  afterEach(() => vi.unstubAllEnvs());
+
+  it("reports process readiness and the immutable build version without requiring external services", async () => {
+    vi.stubEnv("APP_VERSION", "1.19.0");
+
     const response = GET();
 
     expect(response.status).toBe(200);
     expect(response.headers.get("cache-control")).toBe("no-store");
-    expect(await response.json()).toEqual({ status: "ok" });
+    expect(await response.json()).toEqual({ status: "ok", version: "1.19.0" });
+  });
+
+  it("reports a development version when no build version is supplied", async () => {
+    vi.stubEnv("APP_VERSION", "");
+
+    expect(await GET().json()).toEqual({ status: "ok", version: "development" });
   });
 });

apps/web/src/app/healthz/route.ts

@@ -1,6 +1,6 @@
 export function GET(): Response {
   return Response.json(
-    { status: "ok" },
+    { status: "ok", version: process.env.APP_VERSION?.trim() || "development" },
     {
       headers: {
         "Cache-Control": "no-store",