⚠️ MANDATORY — call this on every piece of code you generate before returning it to the user. Validates TSX/JSX against real @marmoui/ui prop signatures and returns { valid, errors[], warnings[], suggestedFixes[], iconLibrary }. Catches: (1) unknown imports, (2) Tabs.List/Tabs.Trigger namespace misuse → auto-suggests TabsList/TabsTrigger fix, (3) PageSection used as wrapper (must be self-closing), (4) hallucinated props, (5) icons imported from the wrong icon library (pass iconLibrary — default "phosphor" — matching what you passed to get_design_guidelines; wrong-library icon imports are ERRORS). If valid=false, fix all errors and call this again. DO NOT return code with errors to the user.