Shared engine takes shape, all four tracks active

All four repos were active at once for the first time. The main app focused on the shared engine: setting clearer boundaries across the platform, laying out a proper host/client split, and hardening the runtime flow and prompts. GIMP helper landed real functionality — draw line, resize, crop, shapes, and undo all work now (brightness, contrast, and blur still need fixing). Blender helper prepared its next model pass, and the LibreOffice track stayed closely tied to the broader platform effort.