feat: icônes par type de fichier + filtre par type + fix preview PDF

1. Icônes de fichier contextuelles:
   - _fileIcon() JS et _file_icon() Python: mappe l'extension vers emoji
   - 📕 PDF, 🖼️ images, 🐍 Python, 📜 JS/TS, 🌐 HTML, 🎨 CSS,
     📋 JSON, 🗃️ SQL, 💻 Shell, ⚡ PS1, 📝 MD, 📦 archives...
   - Appliqué dans sidebar (board.py) + page workspace (x-for + renderChildren)

2. Preview PDF: ne fetch plus le contenu binaire (caractères bizarres),
   affiche 📕 'PDF Document' dans le popup hover

3. Filtre par type:
   - Chips 📝 Pages | 📕 PDF | 🖼️ Img | 📜 Code | 📄 Text
   - _filterTree() accepte un paramètre fileType
   - Désélection par second clic sur le même chip

app/routers/board.py

@@ -140,6 +140,27 @@ def _build_page_tree(conn, parent_id: int | None, ws_key: str, depth: int = 0, m
     return items
 
 
+def _file_icon(name: str) -> str:
+    """Map file extension to emoji icon."""
+    import re
+    n = name.lower()
+    if re.search(r'\.(png|jpe?g|gif|webp|svg|bmp|ico)$', n): return '🖼️'
+    if n.endswith('.pdf'): return '📕'
+    if re.search(r'\.(md|markdown)$', n): return '📝'
+    if n.endswith('.py'): return '🐍'
+    if re.search(r'\.(js|jsx|ts|tsx)$', n): return '📜'
+    if re.search(r'\.(html?|xml)$', n): return '🌐'
+    if n.endswith('.css'): return '🎨'
+    if n.endswith('.json'): return '📋'
+    if n.endswith('.sql'): return '🗃️'
+    if re.search(r'\.(sh|bash|zsh)$', n): return '💻'
+    if n.endswith('.ps1'): return '⚡'
+    if re.search(r'\.(rs|go|java|rb|php|c|cpp|h|swift|kt|scala|r)$', n): return '📜'
+    if re.search(r'\.(txt|log)$', n): return '📄'
+    if re.search(r'\.(zip|tar|gz|rar|7z)$', n): return '📦'
+    return '📄'
+
+
 def _load_workspace_pages(ws_cookie: str) -> list:
     """Load top-level pages with children for the active workspace."""
     if not ws_cookie:
@@ -153,11 +174,13 @@ def _load_workspace_pages(ws_cookie: str) -> list:
             ).fetchall()
         items = []
         for r in rows:
+            is_folder = r["parent_section"] == "Workspace"
+            title = r["title"] or "Untitled"
             items.append({
-                "db_id": r["id"], "name": r["title"] or "Untitled", 
+                "db_id": r["id"], "name": title,
                 "id": f"page/{r['id']}",
-                "icon": "📁" if r["parent_section"] == "Workspace" else "📄",
-                "is_folder": r["parent_section"] == "Workspace",
+                "icon": "📁" if is_folder else _file_icon(title),
+                "is_folder": is_folder,
                 "children": _load_children(r["id"]),
             })
         return items
@@ -174,11 +197,13 @@ def _load_children(parent_id: int) -> list:
         ).fetchall()
     children = []
     for r in rows:
+        is_folder = r["parent_section"] == "Workspace"
+        title = r["title"] or "Untitled"
         children.append({
-            "db_id": r["id"], "name": r["title"] or "Untitled",
+            "db_id": r["id"], "name": title,
             "id": f"page/{r['id']}",
-            "icon": "📁" if r["parent_section"] == "Workspace" else "📄",
-            "is_folder": r["parent_section"] == "Workspace",
+            "icon": "📁" if is_folder else _file_icon(title),
+            "is_folder": is_folder,
             "children": _load_children(r["id"]),
         })
     return children

app/templates/local_workspace.html

@@ -107,6 +107,12 @@
 .search-clear{background:none;border:none;color:var(--text-tertiary);cursor:pointer;font-size:16px;padding:2px 4px;border-radius:3px;}
 .search-clear:hover{color:var(--text);background:var(--bg-hover);}
 
+/* Filter chips */
+.filter-chips{display:flex;gap:6px;margin-bottom:10px;flex-wrap:wrap;}
+.filter-chip{padding:4px 10px;background:var(--bg-tertiary);border:1px solid var(--border);border-radius:6px;font-size:12px;color:var(--text-secondary);cursor:pointer;transition:all 150ms;}
+.filter-chip:hover{background:var(--bg-hover);color:var(--text);}
+.filter-chip.active{background:var(--accent);color:#fff;border-color:var(--accent);}
+
 /* File preview tooltip */
 .file-preview{position:fixed;z-index:300;background:#1a1a1a;background:var(--bg,#1a1a1a);border:1px solid var(--border-strong,#333);border-radius:10px;box-shadow:0 8px 30px rgba(0,0,0,.5);max-width:400px;min-width:200px;pointer-events:auto;}
 .file-preview-header{padding:8px 12px;font-size:12px;font-weight:600;color:var(--text-secondary,#888);border-bottom:1px solid var(--border,#333);}
@@ -174,6 +180,15 @@
     <button class="search-clear" x-show="searchQuery" @click="searchQuery='';doFilter()" title="Clear">×</button>
   </div>
 
+  <!-- Filter chips -->
+  <div class="filter-chips" x-show="tree.length>0">
+    <button class="filter-chip" :class="{ active: filterType === 'page' }" @click="filterByType('page')" title="FlowDeck pages">📝 Pages</button>
+    <button class="filter-chip" :class="{ active: filterType === 'pdf' }" @click="filterByType('pdf')" title="PDF">📕 PDF</button>
+    <button class="filter-chip" :class="{ active: filterType === 'image' }" @click="filterByType('image')" title="Images">🖼️ Img</button>
+    <button class="filter-chip" :class="{ active: filterType === 'code' }" @click="filterByType('code')" title="Code">📜 Code</button>
+    <button class="filter-chip" :class="{ active: filterType === 'text' }" @click="filterByType('text')" title="Text">📄 Text</button>
+  </div>
+
   <ul class="ws-tree" x-show="displayTree.length>0" @click="handleTreeAction($event)">
     <template x-for="node in displayTree" :key="node.id">
       <li>
@@ -192,7 +207,7 @@
             <span style="width:16px;flex-shrink:0;"></span>
           </template>
 
-          <span class="icon" x-text="node.is_folder ? '📁' : '📄'"></span>
+          <span class="icon" x-text="_fileIcon(node.name, node.is_folder)"></span>
 
           <template x-if="node.is_folder">
             <span class="name folder" @click.stop="navigateToFolder(node.id)" x-text="node.name"></span>
@@ -306,6 +321,7 @@ document.addEventListener('alpine:init', function() {
     })(),
     currentFolder: {{ current_folder_id }},
     searchQuery: '',
+    filterType: '',
 
     // Preview popup
     previewVisible: false,
@@ -360,7 +376,7 @@ document.addEventListener('alpine:init', function() {
       for (var i=0; i<children.length; i++) {
         var c = children[i];
         var hasKids = c.children && c.children.length > 0;
-        var icon = c.is_folder ? '📁' : '📄';
+        var icon = this._fileIcon(c.name, c.is_folder);
         var escName = this.esc(c.name);
         html += '<li><div class="ws-tree-item" style="padding-left:'+(depth*20)+'px" draggable="true"'
              + ' data-folder-id="'+(c.is_folder?c.id:'')+'"'
@@ -499,19 +515,58 @@ document.addEventListener('alpine:init', function() {
       }
     },
 
+    // ── File type icon ──
+    _fileIcon(name, isFolder) {
+      if (isFolder) return '📁';
+      var n = (name || '').toLowerCase();
+      if (/\.(png|jpe?g|gif|webp|svg|bmp|ico)$/.test(n)) return '🖼️';
+      if (/\.pdf$/.test(n)) return '📕';
+      if (/\.(md|markdown)$/.test(n)) return '📝';
+      if (/\.(py)$/.test(n)) return '🐍';
+      if (/\.(js|jsx|ts|tsx)$/.test(n)) return '📜';
+      if (/\.(html?|xml)$/.test(n)) return '🌐';
+      if (/\.css$/.test(n)) return '🎨';
+      if (/\.json$/.test(n)) return '📋';
+      if (/\.sql$/.test(n)) return '🗃️';
+      if (/\.(sh|bash|zsh)$/.test(n)) return '💻';
+      if (/\.ps1$/.test(n)) return '⚡';
+      if (/\.(rs|go|java|rb|php|c|cpp|h|swift|kt|scala|r)$/.test(n)) return '📜';
+      if (/\.(txt|log)$/.test(n)) return '📄';
+      if (/\.(zip|tar|gz|rar|7z)$/.test(n)) return '📦';
+      return '📄';
+    },
+
     // ── Search / Filter ──
     doFilter() {
       var q = (this.searchQuery || '').toLowerCase().trim();
-      if (!q) { this.displayTree = this.tree; return; }
-      this.displayTree = this._filterTree(this.tree, q);
+      var ft = this.filterType || '';
+      if (!q && !ft) { this.displayTree = this.tree; return; }
+      var self = this;
+      this.displayTree = this._filterTree(this.tree, q, ft);
     },
-    _filterTree(nodes, query) {
+    filterByType(type) {
+      this.filterType = (this.filterType === type) ? '' : type;
+      this.doFilter();
+    },
+    _filterTree(nodes, query, fileType) {
       var result = [];
       for (var i=0; i<nodes.length; i++) {
         var n = nodes[i];
-        var filteredChildren = n.children ? this._filterTree(n.children, query) : [];
-        var selfMatches = (n.name || '').toLowerCase().indexOf(query) !== -1;
-        if (selfMatches || filteredChildren.length > 0) {
+        var filteredChildren = n.children ? this._filterTree(n.children, query, fileType) : [];
+        var selfMatches = (n.name || '').toLowerCase().indexOf(query || '') !== -1;
+        // File type filter
+        var typeMatch = true;
+        if (fileType && !n.is_folder) {
+          var nm = (n.name || '').toLowerCase();
+          switch(fileType) {
+            case 'pdf':     typeMatch = /\.pdf$/.test(nm); break;
+            case 'image':   typeMatch = /\.(png|jpe?g|gif|webp|svg|bmp|ico)$/.test(nm); break;
+            case 'code':    typeMatch = /\.(py|js|jsx|ts|tsx|rs|go|java|rb|php|c|cpp|h|swift|kt|scala|r|sh|bash|ps1|sql)$/.test(nm); break;
+            case 'text':    typeMatch = /\.(txt|md|markdown|log)$/.test(nm); break;
+            case 'page':    typeMatch = !/\.(pdf|png|jpe?g|gif|webp|svg|bmp|ico|py|js|jsx|ts|tsx|rs|go|java|rb|php|c|cpp|h|swift|kt|scala|r|sh|bash|ps1|sql|txt|md|markdown|log)$/.test(nm); break;
+          }
+        }
+        if ((selfMatches || filteredChildren.length > 0) && typeMatch) {
           var clone = Object.assign({}, n);
           clone.children = filteredChildren;
           result.push(clone);
@@ -542,6 +597,8 @@ document.addEventListener('alpine:init', function() {
         var url = '/api/files/' + wsId + '/' + encodeURIComponent(node.name);
         if (isImg) {
           this.previewContent = '<img src="'+url+'" style="max-width:380px;max-height:180px;display:block;">';
+        } else if ((node.name||'').toLowerCase().endsWith('.pdf')) {
+          this.previewContent = '<div style="text-align:center;padding:16px;"><span style="font-size:48px;">📕</span><br><span style="color:var(--text-secondary);font-size:12px;">PDF Document</span></div>';
         } else {
           this.previewContent = 'Loading...';
           fetch(url)