feat: menu contextuel repertoire → Sauvegarder recherche + icone dossier

- ContextMenuManager: option Ajouter aux recherches sauvegardees pour repertoires
- _saveDirectorySearch: POST /api/saved-searches avec include_paths=repertoire/**
- Bascule automatique vers longlet Sauvegardes dans le sidebar
- loadSavedSearches: icone folder-search + classe saved-search-dir pour recherches dossier
- Recherches dossier affichent le chemin au lieu d'une query vide

frontend/js/viewer.js

@@ -1038,6 +1038,10 @@ export async function loadSavedSearches() {
     }
     if (empty) empty.style.display = "none";
     list.innerHTML = searches.map(s => {
+      // Detect directory-based saved search (empty query + include_paths)
+      var isDirSearch = (!s.query || s.query.trim() === '') && s.include_paths;
+      var displayQuery = isDirSearch ? (s.include_paths || 'Dossier') : escapeHtml(s.query);
+      var dirIcon = isDirSearch ? '<i data-lucide="folder-search" style="width:14px;height:14px;margin-right:4px;color:var(--accent)"></i>' : '';
       const badges = [];
       if (s.case_sensitive) badges.push('<span class="search-filter-badge">Aa</span>');
       if (s.whole_word) badges.push('<span class="search-filter-badge">wd</span>');
@@ -1047,8 +1051,8 @@ export async function loadSavedSearches() {
       if (s.exclude_paths) pathFilters.push(`<span class="saved-search-path" title="Exclure: ${escapeHtml(s.exclude_paths)}">📤 ${escapeHtml(s.exclude_paths)}</span>`);
       const vaultStr = s.vault && s.vault !== "all" ? `<span class="saved-search-vault">📁 ${escapeHtml(s.vault)}</span>` : "";
       return `
-      <div class="saved-search-item">
-        <div class="saved-search-query">${escapeHtml(s.query)}</div>
+      <div class="saved-search-item${isDirSearch ? ' saved-search-dir' : ''}">
+        <div class="saved-search-query">${dirIcon}${displayQuery}</div>
         <div class="saved-search-meta">
           ${badges.join("")}
           ${vaultStr}