Fix contact form shortcode: rename from contact-form.html to contact.html
Problem: Hugo v0.160 doesn't find shortcode as 'contact_form' when filename is contact-form.html
Solution: Rename to contact.html so shortcode is {{< contact >}}
- Rename shortcodes/contact-form.html → contact.html
- Update contact pages to use {{< contact >}} shortcode
- Remove unused dict initialization line from contact shortcode
- Contact form now works on both English and Italian contact pages
