chore: consolidate contact templates to single location

Remove duplicate contact templates:
- templates/partials/contact_success.html (old, 1.2KB)
- templates/partials/contact_error.html (old, 1.1KB)

The active templates remain in templates/partials/contact/:
- contact-success.html
- contact-error.html

Updated contact.go to use the new template names to match cv_contact.go.
The old templates had inline styles and were larger; the new ones use
external CSS and are more maintainable.

All contact form tests pass (7/7).

internal/handlers/contact.go

@@ -139,7 +139,7 @@ func (h *ContactHandler) renderSuccess(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	w.WriteHeader(http.StatusOK)
 
-	tmpl, err := h.templates.Render("contact_success.html")
+	tmpl, err := h.templates.Render("contact-success")
 	if err != nil {
 		log.Printf("ERROR loading success template: %v", err)
 		// Fallback to simple HTML
@@ -168,7 +168,7 @@ func (h *ContactHandler) renderError(w http.ResponseWriter, r *http.Request, mes
 		"Message": message,
 	}
 
-	tmpl, err := h.templates.Render("contact_error.html")
+	tmpl, err := h.templates.Render("contact-error")
 	if err != nil {
 		log.Printf("ERROR loading error template: %v", err)
 		// Fallback to simple HTML