Redesign the DearPyGui emulator into a two-column layout with an interactive training schema editor and runtime preview.
Add JSON load/save support for ST, SM, MT, and RSMT schemes, including draft normalization, conversion to core schemes, and explicit Apply validation so intermediate edits do not restart or block the preview.
Update manual mode to clamp negative mileage, remove speed from manual positioning, preserve stopped runtime state when reloading schemas, and keep linear rendering visible with span-based drawing.
Fix the core linear pingpong render plan so reverse travel remains visible near endpoints and prefix/postfix colors stay tied to physical sides instead of reversing with heading.
Add C++ and Python regressions for schema conversion, emulator edit behavior, manual mode, linear endpoint visibility, and fixed prefix/postfix colors.
crosstyan
7b0f6a523d