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, 2 insertions, 1 deletions

diff --git a/src/common/types.h b/src/common/types.h
index 91f8a47..40c502f 100644
--- a/src/common/types.h
+++ b/src/common/types.h
@@ -355,7 +355,8 @@ enum yasl_private_event_type {
     YASL_PRIVATE_EVENT_DISPLAY_LOST,
     YASL_PRIVATE_EVENT_PEN,
     YASL_PRIVATE_EVENT_TEXT_EDIT,
-    YASL_PRIVATE_EVENT_REFRESH, /**< No payload; display connection failed. */
+    YASL_PRIVATE_EVENT_REFRESH, /**< No payload; surface contents are needed. */
+    YASL_PRIVATE_EVENT_DISPLAY_RESTORED, /**< No payload; display reconnected after DISPLAY_LOST. */
 };
 
 /** Physical keyboard transition with optional layout labels.