fix(media): centre gravite auteurs + bouton vue partagee + poignee draggable barre

- CartePensees.vue : pre-positionner auteurs sur ecole.x_hint/y_hint + jitter 80px pour eviter le rush initial vers la droite au chargement
- media.vue : bouton Vue partagee repositionne entre Carte plein ecran et Chatbot plein ecran, style homogene avec les autres boutons
- media.vue : poignee draggable sur barre separation carte/chatbot en mode split - ratio clamp 20/80, localStorage media-split-ratio, triggerResize D3 au mouseup, desactivee sur mobile

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pages/media.vue

@@ -24,6 +24,7 @@
             layoutMode === 'carte-full' ? 'carte-full' : '',
             layoutMode === 'chatbot-full' ? 'carte-hidden' : '',
           ]"
+          :style="layoutMode === 'split' ? { flexBasis: carteFlexBasis } : {}"
         >
           <ClientOnly>
             <CartePensees
@@ -54,6 +55,17 @@
             </svg>
             Carte plein ecran
           </button>
+          <button
+            v-if="layoutMode !== 'split'"
+            @click="setLayoutMode('split')"
+            class="toggle-btn"
+            title="Vue partagee"
+          >
+            <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+              <rect x="3" y="3" width="18" height="18" rx="2"/><line x1="3" y1="12" x2="21" y2="12"/>
+            </svg>
+            Vue partagee
+          </button>
           <button
             @click="setLayoutMode('chatbot-full')"
             :class="{ active: layoutMode === 'chatbot-full' }"
@@ -65,17 +77,16 @@
             </svg>
             Chatbot plein ecran
           </button>
-          <button
-            v-if="layoutMode !== 'split'"
-            @click="setLayoutMode('split')"
-            class="toggle-btn toggle-btn-reset"
-            title="Vue partagee"
-          >
-            <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
-              <rect x="3" y="3" width="18" height="18" rx="2"/><line x1="3" y1="12" x2="21" y2="12"/>
-            </svg>
-            Vue partagee
-          </button>
+        </div>
+
+        <!-- Poignee draggable (visible uniquement en mode split, pas sur mobile) -->
+        <div
+          v-if="layoutMode === 'split'"
+          class="split-handle"
+          @mousedown.prevent="onHandleMousedown"
+          title="Redimensionner"
+        >
+          <span class="split-handle-grip"></span>
         </div>
 
         <!-- Slot chatbot inline -->
@@ -86,6 +97,7 @@
             layoutMode === 'chatbot-full' ? 'chatbot-full-mode' : '',
             layoutMode === 'carte-full' ? 'chatbot-hidden' : '',
           ]"
+          :style="layoutMode === 'split' ? { flexBasis: chatbotFlexBasis } : {}"
         >
           <ClientOnly>
             <ChatbotPensees :auteurContext="chatbotAuteur" :inline="true" />
@@ -116,6 +128,8 @@ interface PenseesData { meta: any; ecoles: EcoleData[]; auteurs: AuteurData[] }
 type LayoutMode = 'split' | 'carte-full' | 'chatbot-full'
 
 const STORAGE_KEY = 'media-layout-mode'
+const SPLIT_RATIO_KEY = 'media-split-ratio'
+const DEFAULT_SPLIT_RATIO = 0.66
 
 const ficheOpen = ref(false)
 const ficheAuteurId = ref<string | null>(null)
@@ -124,8 +138,45 @@ const penseesData = ref<PenseesData | null>(null)
 const layoutMode = ref<LayoutMode>('split')
 const cartePenseesRef = ref<{ triggerResize: () => void } | null>(null)
 
+// Ratio de la carte vs chatbot en mode split (0.2 a 0.8)
+const splitRatio = ref(DEFAULT_SPLIT_RATIO)
+const carteFlexBasis = computed(() => `${splitRatio.value * 100}%`)
+const chatbotFlexBasis = computed(() => `${(1 - splitRatio.value) * 100}%`)
+
 const corpusCount = computed(() => penseesData.value?.auteurs.length ?? 0)
 
+// Logique poignee draggable
+let dragStartY = 0
+let dragStartRatio = DEFAULT_SPLIT_RATIO
+let containerHeight = 0
+
+function onHandleMousedown(e: MouseEvent) {
+  dragStartY = e.clientY
+  dragStartRatio = splitRatio.value
+  // Hauteur du layout-container (carte + handle + chatbot)
+  const container = (e.target as HTMLElement)?.closest('.layout-container') as HTMLElement | null
+  containerHeight = container ? container.clientHeight : window.innerHeight
+
+  window.addEventListener('mousemove', onHandleMousemove)
+  window.addEventListener('mouseup', onHandleMouseup)
+}
+
+function onHandleMousemove(e: MouseEvent) {
+  const delta = e.clientY - dragStartY
+  const newRatio = dragStartRatio + delta / containerHeight
+  splitRatio.value = Math.min(0.80, Math.max(0.20, newRatio))
+}
+
+function onHandleMouseup() {
+  window.removeEventListener('mousemove', onHandleMousemove)
+  window.removeEventListener('mouseup', onHandleMouseup)
+  if (typeof window !== 'undefined') {
+    localStorage.setItem(SPLIT_RATIO_KEY, String(splitRatio.value))
+  }
+  // Notifier D3 du resize apres relachement
+  cartePenseesRef.value?.triggerResize()
+}
+
 onMounted(async () => {
   // Restaurer le mode de layout depuis localStorage
   if (typeof window !== 'undefined') {
@@ -133,6 +184,10 @@ onMounted(async () => {
     if (saved && ['split', 'carte-full', 'chatbot-full'].includes(saved)) {
       layoutMode.value = saved
     }
+    const savedRatio = parseFloat(localStorage.getItem(SPLIT_RATIO_KEY) ?? '')
+    if (!isNaN(savedRatio) && savedRatio >= 0.20 && savedRatio <= 0.80) {
+      splitRatio.value = savedRatio
+    }
   }
   try {
     penseesData.value = await $fetch<PenseesData>('/data/auteurs-pensees.json')
@@ -209,11 +264,11 @@ useHead({ title: 'AEP - Media - Carte FRACAS Bonpote' })
 .carte-slot {
   overflow: hidden;
   position: relative;
-  transition: flex-basis 0.3s ease, height 0.3s ease, opacity 0.2s ease;
+  transition: opacity 0.2s ease;
 }
 
 .carte-split {
-  flex: 2 1 0;
+  flex: 0 0 66%;
   min-height: 0;
   opacity: 1;
 }
@@ -270,26 +325,55 @@ useHead({ title: 'AEP - Media - Carte FRACAS Bonpote' })
   border-color: var(--nav-primary);
 }
 
-.toggle-btn-reset {
-  margin-left: auto;
-  background: var(--nav-surface);
-  color: var(--nav-text);
+/* --- Poignee draggable entre carte et chatbot --- */
+.split-handle {
+  flex-shrink: 0;
+  height: 8px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  cursor: row-resize;
+  background: transparent;
+  position: relative;
+  z-index: 10;
+  user-select: none;
 }
 
-.toggle-btn-reset:hover {
-  background: var(--nav-bg-alt);
+.split-handle:hover {
+  background: rgba(180, 170, 160, 0.18);
+}
+
+.split-handle-grip {
+  display: block;
+  width: 32px;
+  height: 4px;
+  border-radius: 2px;
+  background: repeating-linear-gradient(
+    to bottom,
+    rgba(160, 150, 140, 0.55) 0px,
+    rgba(160, 150, 140, 0.55) 1px,
+    transparent 1px,
+    transparent 3px
+  );
+}
+
+/* Masquer la poignee sur mobile (ratio fixe) */
+@media (max-width: 767px) {
+  .split-handle {
+    display: none;
+  }
 }
 
 /* --- Slot chatbot --- */
 .chatbot-slot {
   overflow: hidden;
   position: relative;
-  transition: flex-basis 0.3s ease, height 0.3s ease, opacity 0.2s ease;
+  transition: opacity 0.2s ease;
   border-top: 1px solid rgba(180, 170, 160, 0.28);
 }
 
 .chatbot-split {
-  flex: 1 1 0;
+  flex: 0 0 34%;
   min-height: 0;
   opacity: 1;
 }