feat(simulation): Sprint 19 — 7 server systems

Protocol handshake (#555): HandshakeMessage as first IPC frame,
HandshakeState resource, forward-compatible input handling.

State serialization (#96): serialize_npc_to_frozen/deserialize with
full D-024 axis coverage (10 new optional fields on NpcSaveState).

Scope tags (#98): ScopeTagKind enum, ScopePinned marker, automatic
assignment from KnowledgeGraph and RelationshipGraph.

Timestamp eviction (#97): LastInteractionTick, SimSpacePressure,
BinaryHeap LRU eviction respecting ScopePinned entities.

Save/load (#553): save_to_file/load_from_file via MessagePack,
SaveGame/LoadGame IPC commands, SaveLoadResultWire on snapshot.

Test infrastructure (#200): Layer 3 integration test entry point,
three-layer architecture documented per D-030.

Information boundary tests (#272): 4 negative tests proving no
passive KG leakage, LOS fog holds, tier boundary holds, save
isolation per NPC.

1063 tests passing, 0 failures.

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

server/src/perception/observer/mod.rs

@@ -378,6 +378,9 @@ pub fn compute_observer_snapshot(
         None
     };
 
+    // Consume pending save/load result for this tick (#553).
+    let save_result = buffer.pending_save_result.take();
+
     buffer.snapshot = Some(ObserverSnapshot {
         version: crate::bridge::types::PROTOCOL_VERSION,
         tick: time.tick,
@@ -396,15 +399,21 @@ pub fn compute_observer_snapshot(
         conversation_events,
         conversation_ended,
         follow_state,
-        examine_result,
         character_pressure: pressure_query.iter().next().map(|p| {
             crate::simulation::pressure::CharacterPressureWire::from(p)
         }),
         sound_events,
         rng_seed: sim_rng.as_deref().map(|r| r.seed()),
         poi_list,
-        examine_result: None, // Populated by examine system when #242 lands
+        examine_result: examine_result.map(|e| {
+            crate::bridge::types::ExamineResultWire {
+                entity_id: e.target_entity_id,
+                text: e.text,
+                confidence: crate::bridge::types::KnowledgeConfidence::Direct,
+            }
+        }),
         player_knowledge,
+        save_result,
     });
 }