Adds useDeepLinkNavigate (mounted in ClientNonUIFeatures): listens for the
'lotus-deeplink' DOM CustomEvent that the Tauri shell dispatches when a
matrix:/matrix.to link opens the app, converts matrix: URIs to matrix.to, and
navigates via the same path as useMentionClickHandler (reusing matrix-to.ts
parsers + useRoomNavigate). No-op outside Tauri.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
