Capture errors at the boundaries

[PaulHax]

useGlobalErrorHook only listens for window.error. Async failures — most of what
VolView does — reach nothing: no toast, no bug report, no console entry. Vue render
errors are uncaught too, since Sentry.init({ app }) was the only thing installing
app.config.errorHandler, and Sentry is not configured in deployments.

Scope

• Handle unhandledrejection, routed through the same path as window.error
• Dedupe repeated errors — a broken render fires on every re-render and would flood the message list
• Extend the benign-filter list (precedent: the existing ResizeObserver loop filter) as noise surfaces
• Follow-up: install app.config.errorHandler

Note

The code is small; the blast radius isn't. These failures are silent today, so
capturing them will surface a batch of benign rejections — aborted fetches, cancelled
loads, workers torn down mid-flight.

Open question: should newly-captured errors toast like window.error does, or land
quietly in console + bug report until the noise is known?