test(simulation): sprint 10 — replay loading, content scaling, serialization v9, observer tests

#483: Replay loading in test-client — JSONL file loading, tick-scheduled
PlayerInput sending, 13 unit tests, 3 sample replay files.
#500: Content scaling test — baseline + extra NPC comparative, tick budget
assertion (D-026), determinism check across content packs.
#514: Serialization tests for protocol v9 — blocked_entities roundtrip,
backward compat (v5→v9, v8→v9), regenerated msgpack fixtures.
Observer perception tests for confrontation + walk-away mechanics.

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

server/tests/bridge_ipc.rs

@@ -59,6 +59,7 @@ fn snapshot_roundtrip_over_unix_socket() {
             current_monologue: None,
             pending_recognitions: vec![],
             dialogue_response: None,
+            blocked_entities: vec![],
         };
 
         bridge