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/serialization.rs

@@ -29,6 +29,7 @@ fn test_snapshot(tick: u64, entities: Vec<VisibleEntity>) -> ObserverSnapshot {
         sound_events: vec![],
         conversation_events: vec![],
         conversation_ended: vec![],
+        follow_state: None,
         rng_seed: None,
     }
 }
@@ -46,6 +47,7 @@ fn observer_snapshot_roundtrip() {
             visibility: VisibilitySector::Forward,
             relationship: RelationshipState::Unknown,
             observation: EntityVisibility::Visible,
+            tell_state: None,
         }],
     );
 
@@ -199,6 +201,7 @@ fn all_entity_kind_variants_roundtrip() {
             visibility: VisibilitySector::Forward,
             relationship: RelationshipState::Unknown,
             observation: EntityVisibility::Visible,
+            tell_state: None,
         };
         let snapshot = test_snapshot(0, vec![entity]);
         let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");
@@ -235,6 +238,7 @@ fn snapshot_v2_fields_roundtrip() {
             visibility: VisibilitySector::Forward,
             relationship: RelationshipState::Unknown,
             observation: EntityVisibility::Visible,
+            tell_state: None,
         }],
         visible_tiles: vec![
             VisibleTile {
@@ -263,6 +267,7 @@ fn snapshot_v2_fields_roundtrip() {
         sound_events: vec![],
         conversation_events: vec![],
         conversation_ended: vec![],
+        follow_state: None,
         rng_seed: None,
     };
 
@@ -318,7 +323,7 @@ fn protocol_version_constant_matches_snapshot() {
     let snapshot = test_snapshot(0, vec![]);
     assert_eq!(snapshot.version, PROTOCOL_VERSION);
     assert_eq!(
-        PROTOCOL_VERSION, 12,
+        PROTOCOL_VERSION, 13,
         "bump this assertion when protocol version changes"
     );
 }
@@ -361,6 +366,7 @@ fn all_facing_direction_variants_roundtrip() {
             sound_events: vec![],
             conversation_events: vec![],
             conversation_ended: vec![],
+            follow_state: None,
             rng_seed: None,
         };
         let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");
@@ -839,6 +845,7 @@ fn boundary_value_in_entity_id() {
                 visibility: VisibilitySector::Forward,
                 relationship: RelationshipState::Unknown,
                 observation: EntityVisibility::Visible,
+                tell_state: None,
             }],
         );
         let bytes = rmp_serde::to_vec_named(&snapshot)