feat(images): self-host hero photos from Unsplash

Replaces 10 unique Unsplash hotlinked URLs (12 HTML occurrences across 9 pages) with local copies in images/hero/.

Removes external dependency on images.unsplash.com -- improves perf for Madagascar audience (lower latency vs CDN Unsplash) and ensures site availability if Unsplash CDN policies change.

Total added: ~2.5MB across 10 JPG files.

Refs: MVA WordPress -> static migration plan, Phase B PR #1.

about.html

@@ -61,7 +61,7 @@
   <main id="main">
 
     <!-- HERO -->
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1521737711867-e3b97375f902?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/about-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="about.heroTitle">Qui Sommes-Nous</h1>
         <p data-i18n="about.heroSubtitle">Une entreprise à taille humaine au service de la diaspora</p>
@@ -74,7 +74,7 @@
 
         <div class="story-block animate-on-scroll">
           <div class="story-img">
-            <img src="https://images.unsplash.com/photo-1494412574643-ff11b0a5c1c3?w=800&q=80" alt="Avion cargo en vol — fret aérien MVA Global Fret" loading="lazy">
+            <img src="images/hero/about-cargo.jpg" alt="Avion cargo en vol — fret aérien MVA Global Fret" loading="lazy">
           </div>
           <div>
             <h2 id="story-title" data-i18n="about.story1Title">Notre Mission</h2>
@@ -89,7 +89,7 @@
 
         <div class="story-block reverse animate-on-scroll" style="margin-top: 64px;">
           <div class="story-img">
-            <img src="https://images.unsplash.com/photo-1553413077-190dd305871c?w=800&q=80" alt="Entrepôt logistique — MVA Global Fret" loading="lazy">
+            <img src="images/hero/about-warehouse.jpg" alt="Entrepôt logistique — MVA Global Fret" loading="lazy">
           </div>
           <div>
             <h2 data-i18n="about.story2Title">Notre Engagement</h2>

accueil.html

@@ -67,7 +67,7 @@
   <main id="main">
 
     <!-- HERO -->
-    <section class="hero" style="background-image: url('https://images.unsplash.com/photo-1436491865332-7a61a109cc05?w=1600&q=80');" aria-label="Bannière principale">
+    <section class="hero" style="background-image: url('images/hero/accueil-hero.jpg');" aria-label="Bannière principale">
       <div class="hero-content animate-on-scroll">
         <h1>
           <span data-i18n="home.heroTitle">Fret Aérien</span><br>
@@ -126,7 +126,7 @@
       <div class="container">
         <div class="about-preview">
           <div class="about-preview-img animate-on-scroll">
-            <img src="https://images.unsplash.com/photo-1586528116311-ad8dd3c8310d?w=800&q=80" alt="Équipe MVA Global Fret — fret aérien entre l'Europe et Madagascar" loading="lazy">
+            <img src="images/hero/accueil-team.jpg" alt="Équipe MVA Global Fret — fret aérien entre l'Europe et Madagascar" loading="lazy">
           </div>
           <div class="animate-on-scroll delay-2">
             <h2 id="about-preview-title" data-i18n="home.aboutTitle">Qui sommes-nous ?</h2>

cgv.html

@@ -96,7 +96,7 @@
 
   <main id="main">
 
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1569154941061-e231b4725ef1?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/legal-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="cgv.heroTitle">Conditions Générales de Vente</h1>
         <p data-i18n="cgv.heroSubtitle">Lire et accepter avant toute inscription</p>

contact.html

@@ -57,7 +57,7 @@
   <main id="main">
 
     <!-- HERO -->
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1423666639041-f56000c27a9a?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/contact-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="contact.heroTitle">Contactez-Nous</h1>
         <p data-i18n="contact.heroSubtitle">Inscrivez-vous et commencez à envoyer vos colis dès aujourd'hui</p>

guide-envoi.html

@@ -57,7 +57,7 @@
   <main id="main">
 
     <!-- HERO -->
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1542296332-2e4473faf563?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/guide-envoi-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="guide.heroTitle">Guide d'Envoi</h1>
         <p data-i18n="guide.heroSubtitle">Tout ce que vous devez savoir avant d'envoyer un colis</p>

mentions-legales.html

@@ -79,7 +79,7 @@
 
   <main id="main">
 
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1569154941061-e231b4725ef1?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/legal-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="mentionsLegales.heroTitle">Mentions Légales</h1>
         <p data-i18n="mentionsLegales.heroSubtitle">Informations légales relatives au site MVA Global Fret</p>

politique-confidentialite.html

@@ -88,7 +88,7 @@
 
   <main id="main">
 
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1569154941061-e231b4725ef1?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/legal-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="privacy.heroTitle">Politique de Confidentialité</h1>
         <p data-i18n="privacy.heroSubtitle">Comment nous protégeons vos données personnelles</p>

service-commande.html

@@ -58,7 +58,7 @@
   <main id="main">
 
     <!-- HERO -->
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1607082348824-0a96f2a4b9da?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/service-commande-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="serviceCommande.heroTitle">Service Commande pour Vous</h1>
         <p data-i18n="serviceCommande.heroSubtitle">Nous commandons pour vous sur les sites européens, vous récupérez à Madagascar</p>

tarifs.html

@@ -57,7 +57,7 @@
   <main id="main">
 
     <!-- HERO -->
-    <section class="hero hero-sub" style="background-image: url('https://images.unsplash.com/photo-1624272909636-4995421e37e7?w=1600&q=80');">
+    <section class="hero hero-sub" style="background-image: url('images/hero/tarifs-hero.jpg');">
       <div class="hero-content animate-on-scroll">
         <h1 data-i18n="tarifs.heroTitle">Nos Tarifs</h1>
         <p data-i18n="tarifs.heroSubtitle">Des prix transparents pour un service de qualité</p>