refactor: remove SocialQueryPort — replaced by SocialQuery + FederationAdminQuery

-319 lines. Legacy SocialQueryPort trait, NoopSocialQueryPort,
PanicSocialQueryPort all deleted. Federation repos now implement
FederationAdminQuery (single method). get_users uses FederationAdminQuery.
All other consumers use unified SocialQuery.

crates/application/src/users/deps.rs

@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use domain::ports::{
-    DiaryQuery, EventPublisher, ObjectStorage, SocialQuery, SocialQueryPort, StatsRepository,
+    DiaryQuery, EventPublisher, FederationAdminQuery, ObjectStorage, SocialQuery, StatsRepository,
     UserRepository,
 };
 
@@ -13,7 +13,7 @@ pub struct GetProfileDeps {
 
 pub struct GetUsersListDeps {
     pub user: Arc<dyn UserRepository>,
-    pub social_query_legacy: Arc<dyn SocialQueryPort>,
+    pub federation_admin: Arc<dyn FederationAdminQuery>,
 }
 
 pub struct UpdateProfileDeps {

crates/application/src/users/get_users.rs

@@ -15,7 +15,7 @@ pub async fn execute(
 ) -> Result<UsersListData, DomainError> {
     let (users_result, actors_result) = tokio::join!(
         deps.user.list_with_stats(),
-        deps.social_query_legacy.list_all_followed_remote_actors()
+        deps.federation_admin.list_all_followed_remote_actors()
     );
 
     Ok(UsersListData {