refactor: SocialActor rich queries, migrate remaining handlers, slim SocialQueryPort

SocialQuery returns SocialActor (identity+handle+display_name+avatar_url)
instead of bare SocialIdentity. Migrated get_following_page,
get_followers_page, get_blocked_actors_page to use cases. Moved
get_activity_feed + get_profile from SocialQueryPort to SocialQuery.
Legacy SocialQueryPort remains only for get_users listing.

crates/application/src/users/deps.rs

@@ -1,13 +1,19 @@
 use std::sync::Arc;
 
 use domain::ports::{
-    DiaryQuery, EventPublisher, ObjectStorage, SocialQueryPort, StatsRepository, UserRepository,
+    DiaryQuery, EventPublisher, ObjectStorage, SocialQuery, SocialQueryPort, StatsRepository,
+    UserRepository,
 };
 
 pub struct GetProfileDeps {
     pub stats: Arc<dyn StatsRepository>,
     pub diary: Arc<dyn DiaryQuery>,
-    pub social_query: Arc<dyn SocialQueryPort>,
+    pub social_query: Arc<dyn SocialQuery>,
+}
+
+pub struct GetUsersListDeps {
+    pub user: Arc<dyn UserRepository>,
+    pub social_query_legacy: Arc<dyn SocialQueryPort>,
 }
 
 pub struct UpdateProfileDeps {