feat: implement remote unfollow — wire FederationActionPort through delete_follow handler

crates/presentation/src/handlers/social.rs

@@ -79,13 +79,15 @@ pub async fn delete_follow(
     AuthUser(uid): AuthUser,
     Path(username): Path<String>,
 ) -> Result<StatusCode, ApiError> {
-    if username.contains('@') {
-        return Err(ApiError::BadRequest(
-            "remote unfollow not yet supported".into(),
-        ));
-    }
-    let target = get_user_by_username(&*s.users, &username).await?;
-    unfollow_user(&*s.follows, &*s.events, &uid, &target.id).await?;
+    unfollow_actor(
+        &*s.follows,
+        &*s.users,
+        &*s.federation,
+        &*s.events,
+        &uid,
+        &username,
+    )
+    .await?;
     Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(post, path = "/users/{username}/block", params(("username" = String, Path, description = "Username")), responses((status = 204, description = "Blocked")), security(("bearer_auth" = [])))]