Deprecate Alpine-based Dockerfile to prevent glibc compatibility issues

Changes:
- Renamed Dockerfile.simple → Dockerfile.simple.DEPRECATED
- Added prominent warning about Alpine/musl libc incompatibility
- Updated Makefile docker-agent target to use Dockerfile.ubuntu
- Added production deployment notes in Makefile
- Updated docker-compose.yml with LightRAG environment variables

Reason:
The chorus-agent binary built with 'make build-agent' is linked against
glibc and cannot run on Alpine's musl libc. This causes the runtime error:
"exec /app/chorus-agent: no such file or directory"

Production deployments MUST use Dockerfile.ubuntu for glibc compatibility.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Makefile

@@ -90,10 +90,13 @@ run-hap: build-hap
 	./$(BUILD_DIR)/$(BINARY_NAME_HAP)
 
 # Docker builds
+# NOTE: Always use Dockerfile.ubuntu for production builds!
+# Dockerfile.simple.DEPRECATED uses Alpine which is incompatible with glibc-linked binaries
 .PHONY: docker-agent
 docker-agent:
 	@echo "🐳 Building Docker image for CHORUS agent..."
-	docker build -f docker/Dockerfile.agent -t chorus-agent:$(VERSION) .
+	docker build -f Dockerfile.ubuntu -t chorus-agent:$(VERSION) .
+	@echo "⚠️  IMPORTANT: Production images MUST use Dockerfile.ubuntu (glibc compatibility)"
 
 .PHONY: docker-hap
 docker-hap: