feat: Add Friend interface to manage user relationships

Author: fox3000foxy

src/interfaces/User.ts

@@ -55,3 +55,10 @@ export interface Oauth2User {
   discord_id?: string;
   google_id?: string;
 }
+
+export interface Friend {
+  user_1: string;
+  user_2: string;
+  datetime?: string;
+  status: 'pending' | 'approved';
+}