refactor(gpu): move beginRenderPass from GPUCanvas to Context (#12579) 1cac286905

* refactor(gpu): move beginRenderPass from GPUCanvas to Context; canvas is now a 1x presentation target only

* style: clang-format

* fix: out-of-line dtor for ScriptedGPURenderPass; unique_ptr needs complete ore::RenderPass

* fix(gpu render pass): dangling label ptr, missing MSAA-source check, GC-without-finish UAF, stale wrapper after auto-finish

Co-authored-by: Luigi Rosso <luigi-rosso@users.noreply.github.com>