Decouple TemplateFunc from templ.Component by introducing a generic HTMLComponent interface that both templ and pongo2 satisfy via Go structural typing. Add a complete pongo2 rendering engine in templates/pongo/ with page templates, block templates (with BlockContext injection and icon processing), template overrides, and email wrappers. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>