[ide-mode] Update installation logic and nudge (#6068)

packages/core/src/ide/ide-installer.ts

@@ -147,31 +147,11 @@ class VsCodeInstaller implements IdeInstaller {
   }
 }
 
-class OpenVSXInstaller implements IdeInstaller {
-  async install(): Promise<InstallResult> {
-    // TODO: Use the correct extension path.
-    const command = `npx ovsx get google.gemini-cli-vscode-ide-companion`;
-    try {
-      child_process.execSync(command, { stdio: 'pipe' });
-      return {
-        success: true,
-        message:
-          'VS Code companion extension was installed successfully from OpenVSX. Please restart your terminal to complete the setup.',
-      };
-    } catch (_error) {
-      return {
-        success: false,
-        message: `Failed to install VS Code companion extension from OpenVSX. Please try installing it manually.`,
-      };
-    }
-  }
-}
-
 export function getIdeInstaller(ide: DetectedIde): IdeInstaller | null {
   switch (ide) {
     case DetectedIde.VSCode:
       return new VsCodeInstaller();
     default:
-      return new OpenVSXInstaller();
+      return null;
   }
 }