fix(diagnostics): log renderer state on each beginFrame for AMD crash

Add per-frame LOG_WARNING with this/vkCtx/camera/postProcess pointers and
msaaChangePending state. If the log prints before crash, the pointer values
tell us what's corrupt. If it doesn't print, crash is in the log itself
(meaning this or vkCtx is corrupt).

src/rendering/renderer.cpp

@@ -808,6 +808,14 @@ void Renderer::beginFrame() {
     if (!vkCtx) return;
     if (vkCtx->isDeviceLost()) return;
 
+    // Diagnostic: log pointer state to detect corrupt this/members
+    LOG_WARNING("beginFrame: this=", (void*)this,
+                " vkCtx=", (void*)vkCtx,
+                " msaaP=", msaaChangePending_,
+                " ppPipe=", (void*)postProcessPipeline_.get(),
+                " cam=", (void*)camera.get(),
+                " swDirty=", vkCtx->isSwapchainDirty());
+
     // Apply deferred MSAA change between frames (before any rendering state is used)
     g_crashRenderPhase = "bf:msaa";
     if (msaaChangePending_) {