fix(vulkan): re-allocate megaBoneSet_ after descriptor pool reset and fix PlayerFrame ImGui crash

Re-allocate megaBoneSet_[0..1] in M2Renderer::clear() after vkResetDescriptorPool invalidates all
sets from boneDescPool_. Stale handles were bound to command buffers during rendering, causing
cascading validation errors. Also add ImGui::Dummy() after SetCursorScreenPos in the shaman totem
bar to satisfy ImGui's window boundary extension assertion.

src/ui/game_screen_frames.cpp

@@ -464,6 +464,7 @@ void GameScreen::renderPlayerFrame(game::GameHandler& gameHandler) {
                 }
             }
             ImGui::SetCursorScreenPos(ImVec2(cursor.x, cursor.y + slotH + 2.0f));
+            ImGui::Dummy(ImVec2(totalW, 0.0f));
         }
     }