Mark deprecated PrimeNG CSS classes with TODO comments

For every HTML template that references a CSS class removed in PrimeNG 18 (.p-link, .p-highlight, .p-fluid), inserts a <!-- TODO: ... --> comment immediately before the offending element and writes a row to the ManualMigrationSteps data table. The class itself is left in place — the replacements are context-dependent (component-specific selectors, the new fluid input, etc.) and need a human or AI agent to apply.