fix: chargement tree sidebar 100% client-side (pas de asyncio.run)

Avant: _sidebar_data() utilisait asyncio.run() → RuntimeWarning + 302 redirects
Après: gitea_workspace.html appelle loadSidebarTree() → fetch API → injecte dans #sidebar-workspace-items

- base.html: ajout id='sidebar-workspace-items' sur le <ul> workspace
- dashboard.py: _sidebar_data() ne fait plus de fetch serveur, juste passe owner/repo

app/templates/base.html

@@ -167,7 +167,7 @@
   {% endfor %}
 {% endmacro %}
       <div class="sidebar-section-items" x-show="sectionsOpen.workspace" x-transition>
-        <ul class="sidebar-items" data-section="workspace">
+        <ul class="sidebar-items" data-section="workspace" id="sidebar-workspace-items">
           {% if workspace_pages %}
             {{ render_workspace_tree(workspace_pages) }}
           {% else %}

app/templates/gitea_workspace.html

@@ -113,10 +113,36 @@ function giteaWorkspace() {
     init() {
       // Set cookie for sidebar
       document.cookie = 'flowdeck_workspace=gitea:' + this.owner + ':' + this.repo + ';path=/;SameSite=Lax';
+      // Load root tree into sidebar
+      this.loadSidebarTree();
       // Listen for sidebar clicks on Gitea items
       this.setupSidebarClicks();
     },
 
+    async loadSidebarTree() {
+      try {
+        var r = await fetch('/api/gitea/projects/' + this.owner + '/' + this.repo + '/tree');
+        if (!r.ok) return;
+        var d = await r.json();
+        var items = d.tree || [];
+        var container = document.getElementById('sidebar-workspace-items');
+        if (!container) return;
+        container.innerHTML = '';
+        var self = this;
+        items.forEach(function(item) {
+          var icon = item.type === 'folder' ? '📁' : '📄';
+          var li = document.createElement('li');
+          li.className = 'sidebar-item';
+          li.setAttribute('data-gitea-path', item.path);
+          li.setAttribute('data-gitea-type', item.type === 'folder' ? 'folder' : 'file');
+          li.setAttribute('data-gitea-sha', item.sha || '');
+          li.style.cssText = 'padding-left:12px;cursor:pointer;';
+          li.innerHTML = '<span class=\"page-icon\">' + icon + '</span><span class=\"page-name\">' + item.name + '</span>';
+          container.appendChild(li);
+        });
+      } catch(e) { console.error('Sidebar tree load failed:', e); }
+    },
+
     setupSidebarClicks() {
       var self = this;
       document.addEventListener('click', function(e) {