feat: points 11a + 11b — Indicateur AI Actif & Page d'accueil voute

Point 11a — Indicateur AI Actif:
- Badge sync flashe en blanc pendant traitement AI (animation CSS)
- Événements ai-processing-start/end dans ai.js
- Section statut IA dans panneau sync (configurée/non configurée/en cours)
- Endpoint GET /api/ai/status vérifiant les clés API configurées

Point 11b — Page d'accueil de voute:
- Endpoint GET /api/vault/{vault}/files?dir=... (trié par mtime)
- Module vaulthome.js: affichage style résultats de recherche
- Breadcrumb navigable, mise à jour auto sur clic dossier dans tree
- Déclenché auto quand un vault spécifique est sélectionné

frontend/js/sync.js

@@ -246,6 +246,9 @@ function initSyncStatus() {
   });
 
   IndexUpdateManager.connect();
+
+  // Initialize AI status tracking
+  _initAIStatus();
 }
 
 function toggleSyncPanel() {
@@ -323,6 +326,118 @@ function _renderSyncPanel(panel) {
   }
 
   panel.innerHTML = html;
+
+  // ── AI Status section ──
+  _renderAIStatusSection(panel);
+}
+
+// ---------------------------------------------------------------------------
+// AI Status Indicator (inside sync panel + header badge animation)
+// ---------------------------------------------------------------------------
+
+let _aiProcessing = false;
+let _aiStatusChecked = false;
+let _aiConfigured = null; // null = unknown, true/false
+
+/** Check if AI is configured by calling the status endpoint. */
+async function _checkAIStatus() {
+  if (_aiStatusChecked) return;
+  try {
+    const resp = await api('/api/ai/status');
+    _aiConfigured = !!(resp && resp.configured);
+  } catch (e) {
+    _aiConfigured = false;
+  }
+  _aiStatusChecked = true;
+}
+
+function _renderAIStatusSection(panel) {
+  const section = document.createElement('div');
+  section.className = 'sync-panel__ai-section';
+  section.id = 'sync-panel-ai';
+
+  let statusIcon, statusText, statusClass;
+  if (_aiProcessing) {
+    statusIcon = 'loader';
+    statusText = 'Traitement en cours…';
+    statusClass = 'sync-panel__ai--processing';
+  } else if (_aiConfigured === true) {
+    statusIcon = 'check-circle';
+    statusText = 'IA configurée et active';
+    statusClass = 'sync-panel__ai--active';
+  } else if (_aiConfigured === false) {
+    statusIcon = 'x-circle';
+    statusText = 'IA non configurée';
+    statusClass = 'sync-panel__ai--inactive';
+  } else {
+    statusIcon = 'help-circle';
+    statusText = 'Statut IA inconnu';
+    statusClass = 'sync-panel__ai--unknown';
+  }
+
+  section.innerHTML = `
+    <div class="sync-panel__ai-header">
+      <span class="sync-panel__ai-title">Intelligence Artificielle</span>
+      <span class="sync-panel__ai-state ${statusClass}" data-lucide-icon="${statusIcon}">
+        <i data-lucide="${statusIcon}" style="width:14px;height:14px"></i>
+        ${statusText}
+      </span>
+    </div>
+  `;
+
+  panel.appendChild(section);
+  // Trigger icon refresh via global
+  if (window._obsigateRefreshIcons) window._obsigateRefreshIcons();
+}
+
+/** Update the AI section in the open sync panel. */
+function _updateAIStatusInPanel() {
+  const section = document.getElementById('sync-panel-ai');
+  if (!section) return;
+  section.innerHTML = '';
+  const panel = document.getElementById('sync-panel');
+  if (panel) {
+    // Re-render just the AI section
+    const oldSection = panel.querySelector('.sync-panel__ai-section');
+    if (oldSection) oldSection.remove();
+    _renderAIStatusSection(panel);
+  }
+}
+
+/** Flash the sync badge white during AI processing. */
+function _setBadgeAIProcessing(active) {
+  const badge = document.getElementById('sync-badge');
+  if (!badge) return;
+  if (active) {
+    badge.classList.add('sync-badge--ai-processing');
+  } else {
+    badge.classList.remove('sync-badge--ai-processing');
+  }
+}
+
+/** Initialize AI status tracking. */
+function _initAIStatus() {
+  // Listen for AI processing events from ai.js
+  document.addEventListener('ai-processing-start', () => {
+    _aiProcessing = true;
+    _setBadgeAIProcessing(true);
+    _updateAIStatusInPanel();
+  });
+
+  document.addEventListener('ai-processing-end', () => {
+    _aiProcessing = false;
+    _setBadgeAIProcessing(false);
+    _updateAIStatusInPanel();
+  });
+
+  // Check AI status on first sync panel open
+  const badge = document.getElementById('sync-badge');
+  if (badge) {
+    const origClick = badge.onclick;
+    badge.addEventListener('click', () => {
+      _checkAIStatus().then(() => _updateAIStatusInPanel());
+    }, { once: false });
+  }
 }
 
 // ---------------------------------------------------------------------------