fix(simulation): resolve duplicate examine_result field and regenerate fixtures

Removed duplicate examine_result from ObserverSnapshot (old ExamineResultEvent
superseded by ExamineResultWire). Fixed serde_default test version assertion.
Regenerated golden file and all fixture .msgpack files. 1070 Rust tests passing.

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

server/tests/golden/proof_room_tick_10.json

@@ -39,7 +39,6 @@
       "z": 0
     }
   ],
-  "examine_result": null,
   "follow_state": null,
   "game_time": {
     "day": 0,