feat: add email field to business wizard, update success message

- Add email input field after textareas, before checkboxes
- Email required via both HTML 'required' attribute and JS validation
- POST email field to webhook as 'email' key
- Add .biz-field input[type='email'] CSS (inline + external) matching textarea style
- Update success message: 'We will email you the report once it is ready. AI generation typically takes 1-2 minutes.'
- Remove reference to new window / auto-download (no longer opens window)

script.js

@@ -592,6 +592,9 @@ var si = 0,
                     var challenges = document.getElementById('bizChallenges').value.trim();
                     if (!description || !goals || !challenges) return;
 
+                    var email = document.getElementById('bizEmail').value.trim();
+                    if (!email) return;
+
                     var hasHomepage = document.getElementById('bizHasHomepage').checked;
                     var usesOdoo = document.getElementById('bizUsesOdoo').checked;
                     var hasDeveloper = document.getElementById('bizHasDeveloper').checked;
@@ -607,6 +610,7 @@ var si = 0,
                     f.style.display = 'none';
 
                     var fields = {
+                        email: email,
                         description: description,
                         goals: goals,
                         challenges: challenges,
@@ -626,7 +630,7 @@ var si = 0,
                     f.submit();
                     f.remove();
 
-                    /* Show success message — download will start automatically */
+                    /* Show success message — we'll email the report */
                     form.style.display = 'none';
                     success.style.display = 'block';
                 });