[client] egl: snapshot DMA frames before release

Copy imported IVSHMEM frames into renderer-owned textures before
acknowledging their LGMP messages. Hold each lease until its copy fence
signals, and protect selected snapshots until rendering completes.

Track independent delivery lanes, drain acknowledgements on the frame
thread, and recover stale queue subscriptions after host timeouts.

common/include/common/types.h

@@ -23,6 +23,8 @@
 
 #include <stdint.h>
 
+typedef void (*LG_FrameReleaseFn)(void * opaque, uint64_t handle);
+
 struct Point
 {
   int x, y;