fix: acp/zed race condition between MCP initialisation and prompt (#20205)

Signed-off-by: Kartik Angiras <angiraskartik@gmail.com>

packages/a2a-server/src/config/config.test.ts

@@ -28,6 +28,7 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
       const mockConfig = {
         ...params,
         initialize: vi.fn(),
+        waitForMcpInit: vi.fn(),
         refreshAuth: vi.fn(),
         getExperiments: vi.fn().mockReturnValue({
           flags: {
@@ -94,6 +95,7 @@ describe('loadConfig', () => {
           const mockConfig = {
             ...(params as object),
             initialize: vi.fn(),
+            waitForMcpInit: vi.fn(),
             refreshAuth: vi.fn(),
             getExperiments: vi.fn().mockReturnValue({
               flags: {

packages/a2a-server/src/config/config.ts

@@ -166,6 +166,8 @@ export async function loadConfig(
 
   // Needed to initialize ToolRegistry, and git checkpointing if enabled
   await config.initialize();
+
+  await config.waitForMcpInit();
   startupProfiler.flush(config);
 
   await refreshAuthentication(config, adcFilePath, 'Config');