feat: Clean up app/extensions directory before each build

Added directory cleanup logic to remove ./app/extensions before generating
new extension files. This prevents old/stale/removed extensions from
remaining in subsequent builds.

Changes:
- Added fs.rmSync to remove extensions directory if it exists
- Cleanup happens at the start of generateExtensionFiles()
- Directory is recreated during generation process
- Logs cleanup action for visibility

This ensures each build starts with a clean slate and only includes
currently installed extensions.

console/lib/fleetbase-extensions-generator/index.js

@@ -50,6 +50,13 @@ module.exports = {
     },
 
     async generateExtensionFiles() {
+        // Clean up old/stale extensions directory before generating new files
+        const extensionsDir = path.join(this.project.root, 'app', 'extensions');
+        if (fs.existsSync(extensionsDir)) {
+            console.log('[Fleetbase] Cleaning up old extensions directory...');
+            fs.rmSync(extensionsDir, { recursive: true, force: true });
+        }
+
         const extensions = await this.getExtensions();
 
         if (extensions.length === 0) {