[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.

client/renderers/OpenGL/opengl.c

@@ -396,10 +396,19 @@ bool opengl_onFrameFormat(LG_Renderer * renderer, const LG_RendererFormat format
 
 bool opengl_onFrame(LG_Renderer * renderer, const FrameBuffer * frame, int dmaFd,
     const FrameDamageRect * damage, int damageCount,
-    LG_RendererFrameToken frameToken)
+    LG_RendererFrameToken frameToken, LG_FrameReleaseFn releaseFn,
+    void * releaseOpaque, uint64_t releaseHandle)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
 
+  /* The legacy renderer retains the shared framebuffer until render. It does
+   * not support asynchronous DMA ownership. */
+  if (releaseFn)
+    return false;
+
+  (void)releaseOpaque;
+  (void)releaseHandle;
+
   LG_LOCK(this->frameLock);
   this->frame             = frame;
   this->pendingFrameToken = frameToken;