v1.2.8

Enhancements

• Allow cancelling client-side navigation (#4332)
  You can now listen for the phx:before-navigate event and call event.preventDefault() to cancel the navigation synchronously.
  This is mostly useful to prevent a "do you really want to leave" scenario when a user has unsaved changes, combined with a beforeunload listener.
• Sign LiveView upload tokens as :local to avoid node names being included in the token
• Ensure async tasks exit gracefully in LiveView tests (#4348)
• Allow opting focused form elements into DOM patching (#4339)

Bug fixes

• Fix server close handler not being reattached after a manual disconnect + connect (#4341)
• Fix detail.lock() promise in phx:push event never resolving (#4351)
• Fix live components not being correctly patched when changing their DOM ID (#4338)
• Gracefully handle missing upload refs (#4354)