fix: Update db-init target to use Python script

The Makefile was looking for scripts/db/init.sh which doesn't exist.
Updated to call scripts/db/init_schema.py instead.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Makefile

@@ -69,11 +69,7 @@ docker-logs: ## View container logs
 
 db-init: ## Initialize database schema
 	@echo "$(GREEN)Initializing database schema...$(NC)"
-	@if [ -f scripts/db/init.sh ]; then \
-		bash scripts/db/init.sh; \
-	else \
-		echo "$(YELLOW)scripts/db/init.sh not found - skipping$(NC)"; \
-	fi
+	$(PYTHON) scripts/db/init_schema.py
 
 db-reset: ## Drop and recreate database (DESTRUCTIVE)
 	@echo "$(YELLOW)WARNING: This will delete all data!$(NC)"