🤖 fix: restore React DevTools by reverting to dynamic import

The refactor in a55417a changed from using dynamic import() inside
app.whenReady() to using require() at module load time. This broke
React DevTools because electron-devtools-installer accesses Electron
APIs that aren't available until the app is ready.

Reverted to the working approach from commit 1e08943 that uses
await import() inside the app.whenReady() handler.

_Generated with `mux`_

Author: ammar-agent

src/desktop/main.ts

@@ -25,33 +25,7 @@ import assert from "@/common/utils/assert";
 import { loadTokenizerModules } from "@/node/utils/main/tokenizer";
 
 // React DevTools for development profiling
-// Using require() instead of import since it's dev-only and conditionally loaded
-interface Extension {
-  name: string;
-  id: string;
-}
-
-type ExtensionInstaller = (
-  ext: { id: string },
-  options?: { loadExtensionOptions?: { allowFileAccess?: boolean } }
-) => Promise<Extension>;
-
-let installExtension: ExtensionInstaller | null = null;
-let REACT_DEVELOPER_TOOLS: { id: string } | null = null;
-
-if (!app.isPackaged) {
-  try {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    const devtools = require("electron-devtools-installer") as {
-      default: ExtensionInstaller;
-      REACT_DEVELOPER_TOOLS: { id: string };
-    };
-    installExtension = devtools.default;
-    REACT_DEVELOPER_TOOLS = devtools.REACT_DEVELOPER_TOOLS;
-  } catch (error) {
-    console.log("React DevTools not available:", error);
-  }
-}
+// Using dynamic import() to avoid loading electron-devtools-installer at module init time
 
 // IMPORTANT: Lazy-load heavy dependencies to maintain fast startup time
 //
@@ -509,8 +483,12 @@ if (gotTheLock) {
       migrateLegacyMuxHome();
 
       // Install React DevTools in development
-      if (!app.isPackaged && installExtension && REACT_DEVELOPER_TOOLS) {
+      if (!app.isPackaged) {
         try {
+          // eslint-disable-next-line no-restricted-syntax
+          const { default: installExtension, REACT_DEVELOPER_TOOLS } = await import(
+            "electron-devtools-installer"
+          );
           const extension = await installExtension(REACT_DEVELOPER_TOOLS, {
             loadExtensionOptions: { allowFileAccess: true },
           });