refactor(domain): remove ap_id/inbox_url from User and Thought; use ActivityPubRepository lookups

crates/domain/src/ports.rs

@@ -442,6 +442,7 @@ pub trait OutboundFederationPort: Send + Sync {
         author_user_id: &UserId,
         thought: &Thought,
         author_username: &str,
+        in_reply_to_url: Option<&str>,
     ) -> Result<(), DomainError>;
 
     /// Fan out a Delete tombstone for a now-deleted local Note.
@@ -459,6 +460,7 @@ pub trait OutboundFederationPort: Send + Sync {
         author_user_id: &UserId,
         thought: &Thought,
         author_username: &str,
+        in_reply_to_url: Option<&str>,
     ) -> Result<(), DomainError>;
 
     /// Fan out an Announce(object_ap_id) for a boost.