feat(simulation): NpcBlueprint struct design, RON schema, and validator CLI (#611)

Define ZoneSpec, CultureProfile, and NpcBlueprint structs with serde/RON
deserialization. Ship example RON files as schema contract for the copy
team (#609, #610). Add validate-ron CLI for copy team to lint their files
without compiling the server.

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

server/Cargo.toml

@@ -8,6 +8,7 @@ bevy_ecs = "0.18"
 bevy_app = "0.18"
 serde = { version = "1", features = ["derive"] }
 serde_yaml = "0.9"
+ron = "0.8"
 rmp-serde = "1"
 bincode = "1"
 rand = "0.9"