feat(simulation): add YAML to RON converter tool (#403)

Build-time converter reads content YAML and emits RON format. Lives in
tooling/content-converter/ as standalone Rust crate. Runs via make
content-ron. Supports --dry-run, --verbose, --content-type filtering.
Not on critical path — engine consumes YAML in v0.1, RON is future-
proofing for runtime performance.

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

Makefile

@@ -2,7 +2,7 @@ GODOT := $(shell command -v godot4 2>/dev/null || command -v godot 2>/dev/null)
 
 .PHONY: help setup build client server test lint ci ci-client ci-server clean \
        decisions-sync decisions-coverage decisions-active decisions-orphan \
-       db-backup db-install validate-content
+       db-backup db-install validate-content content-ron
 
 # --- Configuration ---
 
@@ -31,6 +31,7 @@ help:
 	@echo "  make decisions-active   List active decisions"
 	@echo "  make decisions-orphan   Decisions without implementing tickets"
 	@echo "  make validate-content  Validate content YAML against schemas"
+	@echo "  make content-ron       Convert content YAML to RON (build-time)"
 	@echo ""
 	@echo "  GODOT_VERSION=4.6 make setup   Override Godot version"
 
@@ -133,6 +134,10 @@ decisions-orphan:
 validate-content:
 	@tooling/validate-content
 
+content-ron:
+	cd tooling/content-converter && cargo build --release
+	tooling/content-converter/target/release/content-converter --input content --output content-ron --verbose
+
 # --- Clean ---
 
 clean: