fix(apps): recover stale npm installs

webui/src/lib/api.ts

@@ -40,7 +40,8 @@ async function request<T>(
     credentials: "same-origin",
   });
   if (!res.ok) {
-    throw new ApiError(res.status, `HTTP ${res.status}`);
+    const text = typeof res.text === "function" ? (await res.text()).trim() : "";
+    throw new ApiError(res.status, text || `HTTP ${res.status}`);
   }
   const contentType = res.headers?.get?.("content-type") ?? "";
   if (contentType && !contentType.toLowerCase().includes("application/json")) {

webui/src/tests/api.test.ts

@@ -134,6 +134,22 @@ describe("webui API helpers", () => {
     });
   });
 
+  it("surfaces API error response bodies", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({
+        ok: false,
+        status: 500,
+        text: async () => "npm error ENOTEMPTY",
+      }),
+    );
+
+    await expect(runCliAppAction("tok", "install", "hyperframes")).rejects.toMatchObject({
+      status: 500,
+      message: "npm error ENOTEMPTY",
+    });
+  });
+
   it("serializes provider settings updates without returning secrets", async () => {
     await updateProviderSettings("tok", {
       provider: "openrouter",