Auto-recover from the known React DOM removeChild/insertBefore race instead of showing the crash page

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Summary

Sentry has been reporting an intermittent crash (issues SHOKO-WEBUI-195 and SHOKO-WEBUI-161):

NotFoundError: Failed to execute 'removeChild' on 'Node': The node to be removed is not a child of this node.

This is a documented React limitation, not specific to React 19 or any particular version: React doesn't support something outside its control (a browser extension, a third-party script) mutating a DOM node it manages. See the official docs ("Avoid changing DOM nodes managed by React") and facebook/react#17256 (still open — a Chrome extension causes this exact error). A later commit's removeChild/insertBefore then targets a node that's already gone. It is not caused by application code.

Investigation

Two independent crash sites were confirmed in Sentry, and neither points to a shared component we can patch:

• /webui/firstrun/start-server (most frequent) — StartServer.tsx polls server status every 500ms while the UI re-renders inside a TransitionDiv (Headless UI <Transition>).
• /webui/collection/filter/live (rarer) — CollectionTitle.tsx, plain conditional JSX with no Headless UI, no react-virtual, no react-modal — nothing exotic.

Several targeted hypotheses were investigated and ruled out with evidence before landing on this fix:

• A redirect race in FirstRunPage was ruled out — isPersistent is set true before polling starts, so the redirect guard can't fire while the crash is observed (confirmed via Sentry session replay).
• A Headless UI Transition-specific bug was ruled out — the second crash site doesn't use Transition (or any DOM-managing library) at all.

The only thing the two sites share is frequent state updates landing near a React commit — the generic signature of this class of bug, which can surface anywhere and isn't fixable by chasing individual components.

Fix

SentryErrorBoundaryWrapper.tsx wraps the whole webui route tree in a single Sentry.ErrorBoundary. Previously, any uncaught error there rendered the disruptive "You Broke The Web UI!" page. This PR adds a fallback that recognizes this specific error signature (error.name === 'NotFoundError' + message matching removeChild/insertBefore) and silently calls resetError() instead, since the underlying app state is intact and only a single DOM commit glitched. A throttle guard (5s) prevents an infinite recovery loop if the error turns out to be persistent rather than transient. Sentry still captures the error for telemetry — only the user-facing crash page is suppressed.

Any other error still falls through to the existing crash page, unchanged.

Verification

• pnpm lint and tsc --noEmit pass clean.
• The recoverable-error predicate was checked against realistic removeChild/insertBefore exceptions plus near-miss cases (unrelated errors, other NotFoundErrors, non-Error throws) to confirm it only catches what it should.
• Not reproducible locally (likely requires a specific browser extension or third-party script), so the fix targets the documented failure mode rather than a local repro.