feat: Ordner erstellen/löschen im File Explorer

Backend (WorkspaceEndpoint.cs):
- POST /api/workspace/mkdir – Ordner im Session-Workspace erstellen
- DELETE /api/workspace/dir – Leeren Ordner im Session-Workspace löschen
- POST /api/workspace/agent/mkdir – Ordner im Agent-Memory erstellen
- DELETE /api/workspace/agent/dir – Leeren Ordner im Agent-Memory löschen
- POST /api/workspace/browse/mkdir – Ordner im Folder-Browser erstellen
- Sicherheit: Path-Traversal-Schutz, Root nicht löschbar, nicht-leer → 409

Frontend (file-explorer.js):
- 📁+ Button im Header für neuen Ordner (File Explorer + Folder Browser)
- 🗑️ Button bei jedem Ordner (erscheint on hover, nur File Explorer)
- Validierung: ungültige Zeichen werden abgelehnt

CSS:
- base.css: Icon-Button mit zwei Icons (folder + plus)
- file-explorer.css: Ordner-Zeile als Flex (Label + Delete-Button)

Endpoints/WorkspaceEndpoint.cs

@@ -41,10 +41,15 @@ public static class WorkspaceEndpoint
         app.MapGet("/api/workspace/file", HandleFile);
         app.MapPut("/api/workspace/file", HandleFileSave);
         app.MapGet("/api/workspace/browse", HandleBrowse);
+        app.MapPost("/api/workspace/browse/mkdir", HandleBrowseMkdir);
         app.MapGet("/api/workspace/agent/tree", HandleAgentTree);
         app.MapGet("/api/workspace/agent/file", HandleAgentFile);
         app.MapPut("/api/workspace/agent/file", HandleAgentFileSave);
         app.MapGet("/api/workspace/raw", HandleRawFile);
+        app.MapPost("/api/workspace/mkdir", HandleMkdir);
+        app.MapDelete("/api/workspace/dir", HandleRmdir);
+        app.MapPost("/api/workspace/agent/mkdir", HandleAgentMkdir);
+        app.MapDelete("/api/workspace/agent/dir", HandleAgentRmdir);
     }
 
     private static async Task HandleTree(HttpContext ctx)
@@ -251,6 +256,38 @@ public static class WorkspaceEndpoint
         await ctx.Response.WriteAsJsonAsync(new { current = targetPath.Replace('\\', '/'), entries });
     }
 
+    private static async Task HandleBrowseMkdir(HttpContext ctx)
+    {
+        var path = ctx.Request.Query["path"].FirstOrDefault();
+        if (string.IsNullOrEmpty(path))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
+            return;
+        }
+
+        var targetPath = Path.GetFullPath(path);
+
+        if (Directory.Exists(targetPath))
+        {
+            ctx.Response.StatusCode = 409;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner existiert bereits" });
+            return;
+        }
+
+        // Parent muss existieren
+        var parent = Path.GetDirectoryName(targetPath);
+        if (string.IsNullOrEmpty(parent) || !Directory.Exists(parent))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Elternverzeichnis nicht gefunden" });
+            return;
+        }
+
+        Directory.CreateDirectory(targetPath);
+        await ctx.Response.WriteAsJsonAsync(new { path = targetPath.Replace('\\', '/'), created = true });
+    }
+
     private static bool IsLikelyTextFile(string name)
     {
         var lower = name.ToLowerInvariant();
@@ -424,6 +461,174 @@ public static class WorkspaceEndpoint
         });
     }
 
+    private static async Task HandleMkdir(HttpContext ctx)
+    {
+        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
+        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
+
+        if (string.IsNullOrEmpty(dirPath))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
+            return;
+        }
+
+        var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
+        var session = await db.GetSession(sessionId ?? "");
+        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
+            return;
+        }
+
+        var basePath = Path.GetFullPath(session.Workspace);
+        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
+
+        if (!targetPath.StartsWith(basePath))
+        {
+            ctx.Response.StatusCode = 403;
+            return;
+        }
+
+        if (Directory.Exists(targetPath))
+        {
+            ctx.Response.StatusCode = 409;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner existiert bereits" });
+            return;
+        }
+
+        Directory.CreateDirectory(targetPath);
+        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, created = true });
+    }
+
+    private static async Task HandleRmdir(HttpContext ctx)
+    {
+        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
+        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
+
+        if (string.IsNullOrEmpty(dirPath))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
+            return;
+        }
+
+        var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
+        var session = await db.GetSession(sessionId ?? "");
+        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
+            return;
+        }
+
+        var basePath = Path.GetFullPath(session.Workspace);
+        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
+
+        if (!targetPath.StartsWith(basePath) || targetPath == basePath)
+        {
+            ctx.Response.StatusCode = 403;
+            return;
+        }
+
+        if (!Directory.Exists(targetPath))
+        {
+            ctx.Response.StatusCode = 404;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner nicht gefunden" });
+            return;
+        }
+
+        if (Directory.GetFileSystemEntries(targetPath).Length > 0)
+        {
+            ctx.Response.StatusCode = 409;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner ist nicht leer" });
+            return;
+        }
+
+        Directory.Delete(targetPath);
+        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, deleted = true });
+    }
+
+    private static async Task HandleAgentMkdir(HttpContext ctx)
+    {
+        var basePath = GetAgentBasePath(ctx, out var error);
+        if (basePath == null)
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error });
+            return;
+        }
+
+        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
+        if (string.IsNullOrEmpty(dirPath))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
+            return;
+        }
+
+        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
+        if (!targetPath.StartsWith(basePath))
+        {
+            ctx.Response.StatusCode = 403;
+            return;
+        }
+
+        if (Directory.Exists(targetPath))
+        {
+            ctx.Response.StatusCode = 409;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner existiert bereits" });
+            return;
+        }
+
+        Directory.CreateDirectory(targetPath);
+        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, created = true });
+    }
+
+    private static async Task HandleAgentRmdir(HttpContext ctx)
+    {
+        var basePath = GetAgentBasePath(ctx, out var error);
+        if (basePath == null)
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error });
+            return;
+        }
+
+        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
+        if (string.IsNullOrEmpty(dirPath))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
+            return;
+        }
+
+        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
+        if (!targetPath.StartsWith(basePath) || targetPath == basePath)
+        {
+            ctx.Response.StatusCode = 403;
+            return;
+        }
+
+        if (!Directory.Exists(targetPath))
+        {
+            ctx.Response.StatusCode = 404;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner nicht gefunden" });
+            return;
+        }
+
+        if (Directory.GetFileSystemEntries(targetPath).Length > 0)
+        {
+            ctx.Response.StatusCode = 409;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner ist nicht leer" });
+            return;
+        }
+
+        Directory.Delete(targetPath);
+        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, deleted = true });
+    }
+
     private static readonly Dictionary<string, string> MimeTypes = new(StringComparer.OrdinalIgnoreCase)
     {
         { ".png", "image/png" }, { ".jpg", "image/jpeg" }, { ".jpeg", "image/jpeg" },

wwwroot/css/base.css

@@ -81,6 +81,13 @@ input {
   flex-shrink: 0;
 }
 
+.icon-btn:has(i + i) {
+  width: 3em;
+  height: 2em;
+  aspect-ratio: unset;
+  margin-right: var(--badge-spacing);
+}
+
 button.icon-btn,
 button.icon-btn:hover {
   border-color: transparent;

wwwroot/css/file-explorer.css

@@ -92,6 +92,33 @@
 
 .fe-dir {
   color: var(--text);
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+}
+
+.fe-dir-label {
+  flex: 1;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.fe-dir-del {
+  opacity: 0;
+  color: var(--text) !important;
+  padding: 2px 6px !important;
+  font-size: .8em;
+  transition: opacity .15s;
+  flex-shrink: 0;
+}
+
+.fe-dir:hover .fe-dir-del {
+  opacity: var(--semi-transparent);
+}
+
+.fe-dir-del:hover {
+  opacity: 1 !important;
+  color: var(--error) !important;
 }
 
 .fe-file {

wwwroot/js/file-explorer.js

@@ -37,6 +37,7 @@ function openFileExplorer(opts = {}) {
         <button class="fe-btn icon-btn" id="feBack" title="Zurück" disabled><i class="fa fa-arrow-left"></i></button>
         <span class="fe-path" id="fePath">/</span>
       </div>
+      <button class="fe-btn icon-btn" id="feNewDir" title="Neuer Ordner"><i class="fa fa-folder-open"></i> <i class="fa fa-plus"></i></button>
       <button class="fe-btn icon-btn" id="feClose"><i class="fa fa-times"></i></button>
     </div>
     <div class="fe-body">
@@ -60,6 +61,7 @@ function openFileExplorer(opts = {}) {
   document.body.appendChild(overlay);
 
   document.getElementById('feBack').addEventListener('click', feGoBack);
+  document.getElementById('feNewDir').addEventListener('click', feCreateDir);
   document.getElementById('feClose').addEventListener('click', closeFileExplorer);
   document.getElementById('feSelectBtn').addEventListener('click', feDoSelect);
   document.getElementById('feSaveBtn').addEventListener('click', feDoSave);
@@ -138,11 +140,24 @@ async function feLoadDir(path) {
 
       if (entry.type === 'dir') {
         item.classList.add('fe-dir');
-        item.innerHTML = '<i class="fa fa-folder"></i> ' + esc(entry.name);
-        item.addEventListener('click', () => {
+        const label = document.createElement('span');
+        label.className = 'fe-dir-label';
+        label.innerHTML = '<i class="fa fa-folder"></i> ' + esc(entry.name);
+        label.addEventListener('click', () => {
           _feState.history.push(path);
           feLoadDir(entry.path);
         });
+        item.appendChild(label);
+
+        const delBtn = document.createElement('button');
+        delBtn.className = 'fe-btn fe-dir-del';
+        delBtn.title = 'Ordner löschen (nur wenn leer)';
+        delBtn.innerHTML = '<i class="fa fa-trash-o"></i>';
+        delBtn.addEventListener('click', (e) => {
+          e.stopPropagation();
+          feDeleteDir(entry.path, entry.name);
+        });
+        item.appendChild(delBtn);
       } else {
         item.classList.add('fe-file');
         const icon = entry.isText ? '<i class="fa fa-file-text-o"></i>' : getFileIcon(entry.ext);
@@ -505,6 +520,7 @@ function openFolderBrowser(opts = {}) {
         <button class="fe-btn icon-btn" id="feBack" title="Zurück" disabled><i class="fa fa-arrow-left"></i></button>
         <span class="fe-path" id="fePath">/</span>
       </div>
+      <button class="fe-btn icon-btn" id="feNewDir" title="Neuer Ordner"><i class="fa fa-folder-open"></i> <i class="fa fa-plus"></i></button>
       <button class="fe-btn icon-btn" id="feClose"><i class="fa fa-times"></i></button>
     </div>
     <div class="fe-body">
@@ -522,6 +538,7 @@ function openFolderBrowser(opts = {}) {
   document.body.appendChild(overlay);
 
   document.getElementById('feBack').addEventListener('click', fbGoBack);
+  document.getElementById('feNewDir').addEventListener('click', fbCreateDir);
   document.getElementById('feClose').addEventListener('click', closeFileExplorer);
   document.getElementById('feSelectBtn').addEventListener('click', () => {
     if (_feState && _feState.onSelect) _feState.onSelect(_feState.currentAbsPath);
@@ -587,6 +604,83 @@ function fbGoBack() {
   fbLoadDir(prev);
 }
 
+// ── Folder Browser: Create Directory ──
+
+async function fbCreateDir() {
+  if (!_feState) return;
+
+  const name = prompt('Ordnername:');
+  if (!name || !name.trim()) return;
+
+  const dirName = name.trim();
+  if (/[\/\\:*?"<>|]/.test(dirName)) {
+    alert('Ungültiger Ordnername');
+    return;
+  }
+
+  const absPath = _feState.currentAbsPath.replace(/\/$/, '') + '/' + dirName;
+
+  try {
+    const resp = await fetch(`/api/workspace/browse/mkdir?path=${encodeURIComponent(absPath)}`, { method: 'POST' });
+    if (!resp.ok) {
+      const err = await resp.json().catch(() => ({}));
+      alert(err.error || 'Fehler beim Erstellen');
+      return;
+    }
+    fbLoadDir(_feState.currentAbsPath);
+  } catch (e) {
+    alert('Netzwerk-Fehler');
+  }
+}
+
+// ── File Explorer: Create / Delete Directory ──
+
+async function feCreateDir() {
+  if (!_feState) return;
+
+  const name = prompt('Ordnername:');
+  if (!name || !name.trim()) return;
+
+  const dirName = name.trim();
+  if (/[\/\\:*?"<>|]/.test(dirName)) {
+    alert('Ungültiger Ordnername');
+    return;
+  }
+
+  const newPath = _feState.currentPath ? _feState.currentPath + '/' + dirName : dirName;
+
+  try {
+    const url = _feApiUrl('mkdir', `path=${encodeURIComponent(newPath)}`);
+    const resp = await fetch(url, { method: 'POST' });
+    if (!resp.ok) {
+      const err = await resp.json().catch(() => ({}));
+      alert(err.error || 'Fehler beim Erstellen');
+      return;
+    }
+    feLoadDir(_feState.currentPath);
+  } catch (e) {
+    alert('Netzwerk-Fehler');
+  }
+}
+
+async function feDeleteDir(dirPath, dirName) {
+  if (!_feState) return;
+  if (!confirm(`Ordner "${dirName}" löschen?\n(Nur möglich wenn leer)`)) return;
+
+  try {
+    const url = _feApiUrl('dir', `path=${encodeURIComponent(dirPath)}`);
+    const resp = await fetch(url, { method: 'DELETE' });
+    if (!resp.ok) {
+      const err = await resp.json().catch(() => ({}));
+      alert(err.error || 'Fehler beim Löschen');
+      return;
+    }
+    feLoadDir(_feState.currentPath);
+  } catch (e) {
+    alert('Netzwerk-Fehler');
+  }
+}
+
 // ── Helpers ──
 
 function getFileIcon(ext) {