30410f2817
Add a new section covering how to write expo tests, including test structure, memory checking, creating test expos, testing rendering and input, building from devicetree, and using IDs. Also add a debugging section with sandbox command-line options useful for expo development. Add a bit more detail for --video_frames Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com> Signed-off-by: Simon Glass <simon.glass@canonical.com>