Fixed AI Administration module (/platform/administration/ai/) — all panel bodies were hidden because BS3 collapse in class does not work in BS5. Converted across 4 files (inc_ai_manager.php, projects.php, billing.php, modules.php): collapse in→collapse show, data-toggle→data-bs-toggle, data-dismiss→data-bs-dismiss. Rebuilt nav-pills tabs with BS5 nav-item/nav-link pattern and fade show active classes. Tab-pane classes updated to use fade+show+active pattern. All 5 AI projects now visible, all 4 tabs functional, all panel sections expanded. Zero PHP errors, zero JS errors.