refactor: update Elysia initialization with API prefix and fix API destination in Next.js config

feat: add targetId for Pixiv and Twitter uploads in post routes
style: adjust filter container margin and button styles for improved layout

apps/backend/src/index.ts

@@ -5,7 +5,7 @@ import openapi from "@elysiajs/openapi";
 
 await mongoose.connect(config.mongodb.uri);
 
-const app = new Elysia()
+const app = new Elysia({prefix: "/api"})
   .use(openapi())
   .get("/", () => "어...")
 

apps/backend/src/routes/post.ts

@@ -422,6 +422,7 @@ export default new Elysia({ prefix: "/post" })
                         role: requester.role,
                     },
                     action: "post.upload.pixiv",
+                    targetId: pixivData.illust_id,
                     targetType: "post",
                     summary: `${requester.username} uploaded Pixiv media`,
                     detail: {
@@ -537,6 +538,7 @@ export default new Elysia({ prefix: "/post" })
                                 role: requester.role,
                             },
                             action: "post.upload.twitter",
+                            targetId: tweetData.tweet.id,
                             targetType: "post",
                             summary: `${requester.username} uploaded Twitter media`,
                             detail: {