Crafting Calculator

Page migration in progress. The crafting calculator is a substantial standalone widget (~45KB of CSS + JS in the legacy craft_calc.php). To finish porting:

1. Open /legacy/craft_calc.php and copy everything between <main> tags into this MainContent placeholder.
2. Move the inline <style> block to the HeadContent placeholder (or to a dedicated CSS file in /Content/).
3. Move the inline <script> block to /Scripts/craft_calc.js and reference it via <asp:Content ContentPlaceHolderID="ScriptsContent">.