Analyzes, builds, modifies, and adds explainer text cards to Mixpanel dashboards with the mixpanel_headless Python library. It reads a dashboard's layout and runs every report on it, creates dashboards with text cards and a grid layout, edits cells and rows in place, and writes data-driven explainer cards. Use when the user asks to analyze, summarize, explain, build, create, redesign, update, reorganize, or clean up a Mixpanel dashboard; asks about dashboard layout, rows, cell widths, text cards, or which chart type suits a board; or wants to turn queries into reports placed on a dashboard. Do not use for general analytics questions or one-off queries (use mixpanelyst), or for what a specific user did in a session recording (use session-replay).