Fix integration test race condition with AI SDK dynamic imports

## Problem

Integration tests were failing in CI with:
"Failed to create model: ReferenceError: You are trying to `import` a
file outside of the scope of the test code."

This only occurred when multiple tests ran concurrently in CI, not locally.

## Root Cause

AI SDK providers use dynamic imports for lazy loading (to optimize startup
time from 6-13s → 3-6s). Under high concurrency in CI (8 workers × 11 test
files × concurrent tests within files), Jest/Bun's module resolution has a
race condition where multiple simultaneous dynamic imports of the same
module can fail.

## Solution

Preload AI SDK providers once during test setup, similar to how we preload
tokenizer modules. This ensures subsequent dynamic imports hit the module
cache instead of racing.

- Added `preloadAISDKProviders()` function to aiService.ts
- Called during `setupWorkspace()` alongside `loadTokenizerModules()`
- Preserves lazy loading in production (startup optimization)
- Eliminates race condition in concurrent test environment

## Testing

- ✅ Tests pass locally with concurrent execution
- ✅ No impact on production startup time (preload only in tests)
- ✅ No changes to test behavior, only timing/reliability

Fixes the flaky integration test failures in PR #259.

Author: ammar-agent

src/services/aiService.ts

@@ -90,6 +90,23 @@ if (typeof globalFetchWithExtras.certificate === "function") {
   defaultFetchWithExtras.certificate =
     globalFetchWithExtras.certificate.bind(globalFetchWithExtras);
 }
+
+/**
+ * Preload AI SDK provider modules to avoid race conditions in concurrent test environments.
+ * This function loads @ai-sdk/anthropic and @ai-sdk/openai eagerly so that subsequent
+ * dynamic imports in createModel() hit the module cache instead of racing.
+ *
+ * In production, providers are lazy-loaded on first use to optimize startup time.
+ * In tests, we preload them once during setup to ensure reliable concurrent execution.
+ */
+export async function preloadAISDKProviders(): Promise<void> {
+  await Promise.all([
+    import("@ai-sdk/anthropic"),
+    import("@ai-sdk/openai"),
+  ]);
+}
+
+
 export class AIService extends EventEmitter {
   private readonly METADATA_FILE = "metadata.json";
   private readonly streamManager: StreamManager;

tests/ipcMain/setup.ts

@@ -10,6 +10,7 @@ import { IPC_CHANNELS } from "../../src/constants/ipc-constants";
 import { generateBranchName, createWorkspace } from "./helpers";
 import { shouldRunIntegrationTests, validateApiKeys, getApiKey } from "../testUtils";
 import { loadTokenizerModules } from "../../src/utils/main/tokenizer";
+import { preloadAISDKProviders } from "../../src/services/aiService";
 
 export interface TestEnvironment {
   config: Config;
@@ -154,6 +155,10 @@ export async function setupWorkspace(
   // Without this, tests would use /4 approximation which can cause API errors
   await loadTokenizerModules();
 
+  // Preload AI SDK providers to avoid race conditions with dynamic imports
+  // in concurrent test environments
+  await preloadAISDKProviders();
+
   // Create dedicated temp git repo for this test
   const tempGitRepo = await createTempGitRepo();