Reconnect to a restarted Wayland compositor

Windows now outlive the compositor. On connection loss YASL sends
DISPLAY_LOST instead of closing every window, retries the connection on
a loop timer, rebuilds each toplevel with its title, size, state and GL
context, and sends DISPLAY_RESTORED. CPU windows keep their pixels;
GPU renderers drop Vulkan surfaces and GL objects on loss and rebuild
them on restore.

- Free the dead connection's objects on the next wait, after the
  application has released GPU objects built on them.
- Report a lost connection as an event rather than a failed wait.
- Refuse window and Vulkan surface creation while offline with the new
  YASL_ERROR_DISCONNECTED.
- Close popups, cancel drags and fail pending clipboard requests on loss.
- Print only protocol errors, not ordinary disconnects.
- Examples survive a restart; game.c rebinds its GL context.
- Add an end-to-end test that kills Weston under CPU, GL and Vulkan
  windows and requires them to recover.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/platform/x11/window.c b/src/platform/x11/window.c
index 8129dd5..ef13afe 100644
--- a/src/platform/x11/window.c
+++ b/src/platform/x11/window.c
@@ -2391,6 +2391,7 @@ static int ready(int fd, short events, void *ud)
     struct x11_display *d = (struct x11_display *)base;
     if ((events & (POLLERR | POLLHUP)) && !d->lost) {
         d->lost = true;
+        base->offline = true;
         yasl_private_display_notify_event(base, YASL_PRIVATE_EVENT_DISPLAY_LOST);
         return 0;
     }