fix(federation): fix 27 AP bugs, gaps, and inconsistencies

Round 1 — 18 bug fixes:
- remote likes/boosts now persist in engagement tables
- intern_remote_actor uses name@domain, expanded username to VARCHAR(255)
- PgRemoteActorRepository upsert/find now handles all fields
- update_following_status no longer a no-op, count_followers counts all
- accept/reject follow publishes event before DB mark (atomicity)
- fetch_outbox_page follows pagination via next links
- actor URL canonicalized to /users/{uuid}
- content_to_html escapes single quotes
- WebFinger accepts application/ld+json type
- try_from_ap accepts Article and Page object types
- feed SQL uses parameterized viewer UUID instead of format!
- content cap raised from 500 to 5000 chars
- also_known_as changed from Option<String> to Vec<String>
- connections fetch always triggers from page 1

Round 2 — 9 gap fixes:
- on_announce_removed handler deletes boost row on Undo(Announce)
- on_update handles Person/Service/Group actor profile updates
- sync_remote_actor_to_user syncs remote_actors → users on create/update
- FederationBlockPort: block_by_username sends Block activity to remote
- domain RemoteActor gains inbox_url, shared_inbox_url fields
- remote_actors attachment column (JSONB) with read/write
- .well-known/host-meta endpoint
- 256KB body limit on AP inbox routes
- outbox cleanup job (7-day retention, hourly sweep)

crates/domain/src/models/remote_actor.rs

@@ -8,10 +8,12 @@ pub struct RemoteActor {
     pub avatar_url: Option<String>,
     pub bio: Option<String>,
     pub banner_url: Option<String>,
-    pub also_known_as: Option<String>,
+    pub also_known_as: Vec<String>,
     pub outbox_url: Option<String>,
     pub followers_url: Option<String>,
     pub following_url: Option<String>,
+    pub inbox_url: Option<String>,
+    pub shared_inbox_url: Option<String>,
     pub attachment: Vec<(String, String)>,
     pub last_fetched_at: DateTime<Utc>,
 }

crates/domain/src/ports.rs

@@ -360,15 +360,27 @@ pub trait FederationFetchPort: Send + Sync {
     ) -> Vec<crate::models::actor_connection_summary::ActorConnectionSummary>;
 }
 
+#[async_trait]
+pub trait FederationBlockPort: Send + Sync {
+    async fn block_remote(&self, local_user_id: &UserId, handle: &str) -> Result<(), DomainError>;
+    async fn unblock_remote(&self, local_user_id: &UserId, handle: &str)
+        -> Result<(), DomainError>;
+}
+
 pub trait FederationActionPort:
-    FederationLookupPort + FederationFollowPort + FederationFollowRequestPort + FederationFetchPort
+    FederationLookupPort
+    + FederationFollowPort
+    + FederationFollowRequestPort
+    + FederationFetchPort
+    + FederationBlockPort
 {
 }
 impl<
         T: FederationLookupPort
             + FederationFollowPort
             + FederationFollowRequestPort
-            + FederationFetchPort,
+            + FederationFetchPort
+            + FederationBlockPort,
     > FederationActionPort for T
 {
 }

crates/domain/src/testing/mod.rs

@@ -846,6 +846,24 @@ impl FederationFetchPort for TestStore {
     }
 }
 
+#[async_trait]
+impl FederationBlockPort for TestStore {
+    async fn block_remote(
+        &self,
+        _local_user_id: &UserId,
+        _handle: &str,
+    ) -> Result<(), DomainError> {
+        Ok(())
+    }
+    async fn unblock_remote(
+        &self,
+        _local_user_id: &UserId,
+        _handle: &str,
+    ) -> Result<(), DomainError> {
+        Ok(())
+    }
+}
+
 #[async_trait]
 impl RemoteActorConnectionRepository for TestStore {
     async fn upsert_connections(