fix: silent fetch POST instead of new-window form, update subtitle

- Replace hidden form POST (target='_blank') with silent fetch() that
  ignores the response — no new window opens
- Send boolean values directly instead of serializing to 'true'/'false' strings
- Update subtitle: 'Download your PDF in minutes.' -> 'We will send the report in minutes.'

index.html

@@ -397,7 +397,7 @@
       <div class="container">
         <p class="section-kicker">Bring Your Business</p>
         <h2>Your Personalized Odoo Project Plan</h2>
-        <p class="biz-sub">Tell us about your business. AI prepares a custom project plan with recommended modules, timeline, and roadmap. Download your PDF in minutes.</p>
+        <p class="biz-sub">Tell us about your business. AI prepares a custom project plan with recommended modules, timeline, and roadmap. We will send the report in minutes.</p>
         <form class="biz-form" id="bizForm">
           <div class="biz-field">
             <label for="bizDescription">Business Description</label>