perf: optimize app startup and background lifecycles

tests/unit/host-api-proxy.test.ts

@@ -89,4 +89,28 @@ describe('Host API IPC proxy', () => {
     expect(headers.get('authorization')).toBe('Bearer host-token');
     expect(headers.get('x-niancode-renderer-capability')).toBe('renderer-token');
   });
+
+  it('dispatches short JSON requests in Main without opening loopback HTTP', async () => {
+    const fetchMock = vi.fn();
+    vi.stubGlobal('fetch', fetchMock);
+    vi.doMock('../../electron/api/host-api-dispatcher', () => ({
+      dispatchHostApiRequest: vi.fn().mockResolvedValue({
+        status: 200,
+        ok: true,
+        json: { success: true, transport: 'test' },
+      }),
+    }));
+
+    const { registerHostApiProxyHandlers } = await import('../../electron/main/ipc/host-api-proxy');
+    registerHostApiProxyHandlers({} as never);
+
+    const fetchHandler = handleMock.mock.calls.find(([channel]) => channel === 'hostapi:fetch')?.[1];
+    const result = await fetchHandler(undefined, { path: '/api/app/runtime-info' });
+
+    expect(fetchMock).not.toHaveBeenCalled();
+    expect(result).toEqual({
+      ok: true,
+      data: { status: 200, ok: true, json: { success: true, transport: 'test' }, transport: 'dispatcher' },
+    });
+  });
 });