fix: swap nosotros lead photo and drop header WhatsApp pill

Swap the lead team photo with the service/montaje photo (and give
the displaced group photo a spot in the support grid instead of
dropping it). Also remove the always-visible WhatsApp pill from the
desktop header nav since it duplicated the floating WhatsApp CTA and
the mobile drawer's own WhatsApp button.

src/components/SiteHeader.astro

@@ -37,17 +37,6 @@ const links = [
     </nav>
 
     <div class="nav-actions">
-      <!-- WhatsApp solo en desktop -->
-      <a
-        href="https://wa.me/34678171513?text=Hola%20MNQ%2C%20quiero%20cotizar%20mi%20evento"
-        class="btn btn-pill nav-wa"
-        target="_blank"
-        rel="noreferrer"
-        aria-label={whatsappAriaLabel}
-      >
-        WhatsApp
-      </a>
-
       <!-- Hamburger (mobile) -->
       <button class="nav-toggle" id="navToggle" aria-label="Abrir menú" aria-expanded="false">
         <span class="hb-bar"></span>
@@ -148,13 +137,6 @@ const links = [
     transform: translateY(-7px) rotate(-45deg);
   }
 
-  /* ── WhatsApp pill — oculto en mobile ── */
-  .nav-wa {
-    display: none;
-    font-size: 0.6875rem;
-    padding: 0.625rem 1.25rem;
-  }
-
   /* ── Mobile drawer ── */
   .mobile-nav {
     display: none;
@@ -196,7 +178,6 @@ const links = [
   @media (min-width: 48rem) {
     .site-logo-banner { height: 3.25rem; }
     .nav-toggle        { display: none; }
-    .nav-wa            { display: inline-flex; }
     .mobile-nav        { display: none !important; }
   }
 </style>

src/pages/nosotros.astro

@@ -14,20 +14,20 @@ const heroPhoto = {
 
 const teamGallery = {
   lead: {
-    src: '/images/team/mnq-team-lead.webp',
-    alt: 'Equipo de MNQ durante un servicio',
-    width: 1439,
-    height: 1919,
-    pos: 'center 24%',
+    src: '/images/team/mnq-team-service.jpg',
+    alt: 'Montaje y coordinación del servicio de MNQ',
+    width: 1080,
+    height: 1440,
+    pos: 'center 28%',
   },
   support: [
     {
-      src: '/images/team/mnq-team-service.jpg',
-      alt: 'Montaje y coordinación del servicio de MNQ',
-      width: 1080,
-      height: 1440,
-      pos: 'center 28%',
-      caption: 'Montaje, tiempos y atención coordinados con naturalidad.',
+      src: '/images/team/mnq-team-lead.webp',
+      alt: 'Equipo de MNQ durante un servicio',
+      width: 1439,
+      height: 1919,
+      pos: 'center 24%',
+      caption: 'Equipo al completo, listo para acompañar el servicio.',
     },
     {
       src: '/images/team/mnq-team-kitchen.webp',