complete performance and reliability follow-ups

packages/observability/test/integrations.test.ts

@@ -93,4 +93,14 @@ describe("observability integrations", () => {
     expect(await profile("render", () => "ok")).toBe("ok");
     expect(profiles[0]).toMatchObject({ name: "render", durationMs: 4 });
   });
+
+  test("operation exporter failures reach diagnostics without recursive telemetry", async () => {
+    const diagnostics: string[] = [];
+    const tracer = createOperationTracer({
+      exporter: { export: () => Promise.reject(new Error("offline")) },
+      diagnostic: (message) => diagnostics.push(message),
+    });
+    await expect(tracer.span("database", "query", async () => 1)).resolves.toBe(1);
+    expect(diagnostics).toEqual(["operation span export failed"]);
+  });
 });

packages/observability/test/observability.test.ts

@@ -8,6 +8,8 @@ describe("@wrnexus/observability", () => {
     expect(client).toContain('addEventListener("pagehide", flush');
     expect(client).not.toContain('send("INP",max)');
     expect(client).not.toContain('send("LCP", last.startTime)');
+    expect(client).toContain("web-vitals delivery failed");
+    expect(client).toContain("PerformanceObserver unavailable for");
   });
 
   test("records deterministic counters and histograms", () => {

packages/observability/test/operations.test.ts

@@ -81,6 +81,22 @@ describe("production observability operations", () => {
     expect(failures).toHaveLength(1);
   });
 
+  test("reports exporter failures through the non-recursive diagnostic hook", async () => {
+    const diagnostics: Array<{ message: string; error: unknown }> = [];
+    const ctx = createContext(
+      new Request("https://example.test/"),
+      new URL("https://example.test/"),
+    );
+    const middleware = traceMiddleware({
+      random: (target) => target.fill(8),
+      exporter: { export: () => Promise.reject(new Error("offline")) },
+      diagnostic: (message, error) => diagnostics.push({ message, error }),
+    });
+    expect((await middleware(ctx, () => new Response("ok"))).status).toBe(200);
+    expect(diagnostics).toHaveLength(1);
+    expect(diagnostics[0]?.message).toBe("trace export failed");
+  });
+
   test("exports OTLP JSON traces and metrics", async () => {
     const requests: unknown[] = [];
     const send = (async (_url: URL | RequestInfo, init?: RequestInit) => {