data(client): update msgpack fixtures and golden files for protocol v13

Regenerate all msgpack test fixtures with tell_state and follow_state
fields. Update golden proof_room snapshot. Adjust serialization and
bridge tests for new ObserverSnapshot fields.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/tests/bridge_ipc.rs

@@ -53,6 +53,7 @@ fn snapshot_roundtrip_over_unix_socket() {
                 visibility: VisibilitySector::Forward,
                 relationship: RelationshipState::Unknown,
                 observation: EntityVisibility::Visible,
+                tell_state: None,
             }],
             visible_tiles: vec![],
             nearby_interactions: vec![],
@@ -64,6 +65,7 @@ fn snapshot_roundtrip_over_unix_socket() {
             sound_events: vec![],
             conversation_events: vec![],
             conversation_ended: vec![],
+            follow_state: None,
             rng_seed: None,
         };