feat: soft-delete and undo/restore for local-workspace items

Backend:
- DELETE /api/local-workspace/items/{id} now soft-deletes (sets deleted_at
  instead of hard DELETE) — items go to trash, not permanently gone
- New POST /api/local-workspace/items/{id}/restore to undo a delete
- _load_workspace_pages() and _load_children() now filter deleted_at IS NULL
  so soft-deleted items disappear from sidebar and tree queries

Frontend:
- undoDelete() now calls the restore API per item (single or bulk)
- bulkDelete() now shows the same undo banner as context menu delete
- All delete paths (ctxMenu, bulk, modal) use the same soft-delete + undo flow

app/templates/local_workspace.html

@@ -567,11 +567,20 @@ window._wsInitData = (function() {
       if (ids.length === 0) return;
       if (!confirm('Delete ' + ids.length + ' selected items?')) return;
       var self = this;
+      // Soft-delete all selected items
       for (var i=0; i<ids.length; i++) {
         await fetch('/api/local-workspace/items/' + ids[i], { method: 'DELETE' });
       }
       this.clearSelection();
       this._reloadAfterAction();
+      // Show undo banner for bulk delete
+      this.undoItemId = ids.join(',');
+      this.undoMessage = 'Deleted ' + ids.length + ' item(s)';
+      this.undoVisible = true;
+      this.undoTimeout = setTimeout(function() {
+        self.undoVisible = false;
+        self.undoItemId = null;
+      }, 5000);
     },
     clearSelection() {
       for (var k in this.selectedIds) delete this.selectedIds[k];
@@ -1223,11 +1232,23 @@ window._wsInitData = (function() {
     undoDelete() {
       if (this.undoTimeout) clearTimeout(this.undoTimeout);
       this.undoVisible = false;
-      var id = this.undoItemId;
-      if (!id) return;
-      // Recreate the item (we can't really undo a DELETE, so reload)
-      this._reloadAfterAction();
+      var ids = (this.undoItemId || '').toString().split(',');
       this.undoItemId = null;
+      if (!ids.length || !ids[0]) return;
+      // Restore via API (soft-delete undo) — single or bulk
+      var self = this;
+      var restored = 0;
+      var total = ids.length;
+      function restoreOne(i) {
+        if (i >= total) {
+          self._reloadAfterAction();
+          return;
+        }
+        fetch('/api/local-workspace/items/' + ids[i] + '/restore', { method: 'POST' })
+          .then(function(r) { if (r.ok) restored++; })
+          .finally(function() { restoreOne(i + 1); });
+      }
+      restoreOne(0);
     },
     _removeFromTree(nodes, id) {
       for (var i=0; i<nodes.length; i++) {