refactor(application): move local/remote follow routing out of presentation handler

crates/presentation/src/handlers/social.rs

@@ -57,12 +57,15 @@ pub async fn post_follow(
     AuthUser(uid): AuthUser,
     Path(username): Path<String>,
 ) -> Result<StatusCode, ApiError> {
-    if username.contains('@') {
-        s.federation.follow_remote(&uid, &username).await?;
-    } else {
-        let target = get_user_by_username(&*s.users, &username).await?;
-        follow_user(&*s.follows, &*s.events, &uid, &target.id).await?;
-    }
+    follow_actor(
+        &*s.follows,
+        &*s.users,
+        &*s.federation,
+        &*s.events,
+        &uid,
+        &username,
+    )
+    .await?;
     Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(