chore(docs): remove content-converter and content-ron Makefile target

The YAML→RON converter and its make target are v0.1 artifacts superseded
by the v0.2 RON-first generator pipeline. content-ron/ was already
gitignored; this removes the tool that generated it.

Closes #667.

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 check-protocol client server game stop test lint ci ci-client ci-server clean \
        decisions-sync decisions-coverage decisions-active decisions-orphan \
-       db-backup db-install validate-content content-ron check-fact-ids setup-hooks \
+       db-backup db-install validate-content check-fact-ids setup-hooks \
        pre-pr pre-pr-lint pre-pr-build pre-pr-test pre-pr-validate pre-pr-fixtures \
        pre-pr-server pre-pr-client pre-pr-content \
        fixtures-client fixtures-gauntlet golden-diff golden-update \
@@ -47,7 +47,6 @@ help:
 	@echo "  make decisions-orphan   Decisions without implementing tickets"
 	@echo "  make validate-content   Validate content YAML against schemas"
 	@echo "  make check-fact-ids    Check fact_id references against knowledge catalogs"
-	@echo "  make content-ron       Convert content YAML to RON (build-time)"
 	@echo "  make fixtures-client    Generate GDScript->Rust cross-encoder fixtures (#475)"
 	@echo "  make golden-diff        Show diff if golden file output has changed"
 	@echo "  make golden-update      Regenerate golden file and stage for commit"
@@ -382,10 +381,6 @@ test-voice-real:
 	cd server && cargo test --test voice_pipeline -- --nocapture
 	@echo "Results: .tmp/voice-test/results.txt"
 
-content-ron:
-	cd tooling/content-converter && cargo build --release
-	tooling/content-converter/target/release/content-converter --input content --output content-ron --verbose
-
 # --- Clean ---
 
 clean: