New features and enhancements

• Introduce ui.context_menu (#1738, #1801 by @gavinpotter, @natankeddem, @falkoschindler)
• Introduce validate() method for validation elements (#1781 by @falkoschindler)
• Improve recovery after reconnecting (#1761, #1762, #1763 by @s2terminal, @rodja)
• Adapt socket.io heartbeat depending on the provided reconnect_timeout (#1812 by @rodja)

Bugfixes

• Fix "coroutine 'AsyncServer.enter_room' was never awaited" (#1809 by @FlynV, @Barriradio, @nghia-vo, @falkoschindler)
• Refresh binding before page delivery (#1561, #1775 by @laserir, @falkoschindler)

Documentation

• Improve Fly replay middleware to only replay if the target instance is still available (#1814 by @rodja)
• Fix typo: change "styles" to "style" (#1799 by @frankhuurman)
• Fix script "Script Executor" example on Windows (#1767 by @dotnfc, @rodja)
• Clarify usage of ui.open on auto-index pages (#1760 by @rodja)
• Simplify tree example and showing disable feature (#1759 by @rodja)