feat(utils): Add loadAliases function

This commit introduces a new function `loadAliases` in `utils.ts`. This
function asynchronously loads alias configurations from both SvelteKit
and Vite configurations, merges them, and returns the result. This
enhancement improves the flexibility and configurability of the system.

Author: ryoppippi

src/utils.ts

@@ -0,0 +1,33 @@
+/* eslint-disable ts/no-unsafe-member-access */
+/* eslint-disable ts/no-unsafe-assignment */
+import type { Config as SvelteKitConfig } from '@sveltejs/kit';
+import type { AliasOptions, UserConfig as ViteConfig } from 'vite';
+import { loadConfig } from 'unconfig';
+
+export async function loadAliases(): Promise<AliasOptions> {
+	const { config } = await loadConfig({
+		merge: true,
+		sources: [
+			{
+				files: 'svelte.config',
+				rewrite: (_config) => {
+					const config = _config as SvelteKitConfig;
+					return {
+						alias: config?.kit?.alias ?? {},
+					};
+				},
+			},
+			{
+				files: 'vite.config',
+				rewrite: (_config) => {
+					const config = _config as ViteConfig;
+					return {
+						alias: config?.resolve?.alias ?? {},
+					};
+				},
+			},
+		],
+	});
+	// eslint-disable-next-line ts/no-unsafe-return
+	return config.alias ?? {};
+}