fix: persist note_extensions on AP Update activity

on_update was discarding custom fields (posterUrl, movieTitle, etc),
so remote notes from movies-diary lost posters after Update delivery.

crates/application/Cargo.toml

@@ -19,5 +19,6 @@ bytes       = { workspace = true }
 futures     = { workspace = true }
 
 [dev-dependencies]
-tokio  = { workspace = true, features = ["full"] }
-domain = { workspace = true, features = ["test-helpers"] }
+tokio      = { workspace = true, features = ["full"] }
+domain     = { workspace = true, features = ["test-helpers"] }
+serde_json = { workspace = true }

crates/application/src/testing.rs

@@ -90,7 +90,7 @@ impl ActivityPubRepository for TestApRepo {
     ) -> Result<ThoughtId, DomainError> {
         Ok(ThoughtId::from_uuid(uuid::Uuid::new_v4()))
     }
-    async fn apply_note_update(&self, _ap_id: &str, _new_content: &str) -> Result<(), DomainError> {
+    async fn apply_note_update(&self, _ap_id: &str, _new_content: &str, _: Option<serde_json::Value>) -> Result<(), DomainError> {
         Ok(())
     }
     async fn retract_note(&self, _ap_id: &str) -> Result<(), DomainError> {