fix: correct intro text position and styling to match original CV

User reported intro text was in wrong position (inside Training section).

Changes:
- Moved intro text INSIDE cv-header-left div (GREEN BOX position)
- Positioned right after "20 years of experience"
- Removed duplicate Training section that showed summary
- NO section heading - just the text flowing naturally

CSS Updates:
- Removed .cv-excerpt and .excerpt-text (wrong implementation)
- Added .intro-text with exact styling from old React CV:
  * Font: Quicksand, 1.0em
  * Line height: 1.6
  * Text align: justify
  * Style: italic
  * Margin-top: 20px
  * Color: rgb(51, 51, 51)
- Added responsive styles for mobile (0.9em, 15px margin)

Verified with Playwright analysis of old React CV.
Intro text now appears exactly as in original implementation.

templates/cv-content.html

@@ -87,23 +87,15 @@
             <div class="cv-header-left">
                 <h1 class="cv-name">{{.CV.Personal.Name}}</h1>
                 <p class="cv-experience-years">{{if eq .Lang "es"}}20 años de experiencia{{else}}20 years of experience{{end}}</p>
+                <!-- Intro/Excerpt Text - No section heading, just the text -->
+                <div class="intro-text">{{.CV.Summary}}</div>
             </div>
             <div class="cv-photo">
                 <img src="/static/images/profile/photo.jpg" alt="{{.CV.Personal.Name}}" onerror="this.src='/static/images/profile/placeholder.svg'">
             </div>
         </div>
-        <!-- Intro/Excerpt Text -->
-        <div class="cv-excerpt">
-            <p class="excerpt-text">{{.CV.Summary}}</p>
-        </div>
     </div>
 
-    <!-- Summary -->
-    <section class="cv-section">
-        <h3 class="section-title">{{if eq .Lang "es"}}Resumen{{else}}Training{{end}}</h3>
-        <p class="summary-text">{{.CV.Summary}}</p>
-    </section>
-
     <!-- Education -->
     <section class="cv-section">
         <h3 class="section-title">{{if eq .Lang "es"}}Formación{{else}}Training{{end}}</h3>