Function formatPrintChargesDisplay

Format a mystery / mystical-ability charge pool as static text, mirroring the interactive sheet's rules (#310/#311) with print-safe glyphs, first match wins:

• max disabled → em dash (no charge pool);
• value disabled → infinity (unlimited uses);
• max 0 → "<value>/∞" (tracked but unbounded);
• otherwise → "<value>/<max>".