Use when the Power Apps MVP is already in prd.md and it is time for stage 3 of the pipeline: the Branding Designer Agent defines with the user the colors, fonts, navigation (fixed side menu, collapsible side menu or drawer, top bar or home screen with cards), components and visual identity (ux-design-system.md + visual sample). Also runs in adjustment mode when the prototype came back with change requests. Do not use before /pp-en:brainstorm, or to change the color of a screen that is already built (use `powerapps-canvas`).
