Replaced custom apiGet/apiPost/apiDelete methods with apiClient calls. The apiClient automatically handles JWT authentication from cookies, fixing 401 Unauthorized errors on billing API endpoints. Also replaced showNotification with Utils.showToast for consistency with JS-009 architecture rule. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>