feat: add api controllers and routes for browser extension

app/api/collections/controllers/get_collections_controller.ts

@@ -0,0 +1,16 @@
+import { CollectionService } from '#collections/services/collection_service';
+import { inject } from '@adonisjs/core';
+import { HttpContext } from '@adonisjs/core/http';
+
+@inject()
+export default class GetCollectionsController {
+	constructor(private collectionService: CollectionService) {}
+
+	async show({ response }: HttpContext) {
+		const collections =
+			await this.collectionService.getCollectionsForAuthenticatedUser();
+		return response.json({
+			collections: collections.map((collection) => collection.serialize()),
+		});
+	}
+}