feat: directus插件与组合式函数编写

- plugins：Directus插件
- composable：Directus图片/文件的相关组合式函数

app/composables/useDirectusFiles.ts

@@ -0,0 +1,22 @@
+export const useDirectusFiles = () => {
+  const config = useRuntimeConfig();
+  const baseUrl = config.public.directus.url;
+
+  const getFileUrl = (
+    id?: string | null,
+    options?: Record<string, string | number | boolean>
+  ): string => {
+    if (!id) return '';
+    const query = options
+      ? '?' +
+        new URLSearchParams(
+          Object.entries(options).map(([key, value]) => [key, String(value)])
+        ).toString()
+      : '';
+    return `${baseUrl}/assets/${id}${query}`;
+  };
+
+  return {
+    getFileUrl,
+  };
+};