- documents_loader: skip missing files (print warning + continue) instead
of raising HTTPException inside SSE generator — prevents "response
already started" runtime error when temp files are wiped on restart
- V1ContentRender: wrap non-edit mode render in SlideErrorBoundary so
broken custom layout components show a red placeholder instead of
crashing the page (React error #62)
- CustomTemplateCard: wrap LayoutPreview in SlideErrorBoundary for the
same reason — bad compiled TSX from master deck parsing no longer
crashes the outline template picker
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>