v1.12.1

VNC reliability

• Restore initial VNC attachment for Xvfb launched with -displayfd.
• Preserve per-server display ownership across multi-instance hosts.
• Reattach x11vnc after browser/Xvfb restarts on the same display.
• Add GET /vnc/status for attachment and port discovery.
• Add hermetic watcher coverage and a disposable Linux recovery smoke test.

Includes the VNC work proposed in #4781, #5243, #6549, and #8070. Thanks @Doud-FR, @paranoidi, @modanq, and @luxles.