▣ wi

Sub-item of #995 Add global client-error handler (window.onerror + onunhandledrejection) to Mars for telemetry parity — currently only React-boundary + server errors are captured; async unhandled rejections / raw event-handler throws go uncaptured (no clientWindowError family exists). Additive coverage, not a defect. MUST serialize err.message/.name/.stack as discrete fields (NOT raw object → '[object Object]') per the venus fc69b24 lesson. Surfaced by cross-app applog review. · mars