open as worspace implementation

src/components/ActionsPanel.tsx

@@ -12,6 +12,7 @@ interface ActionsPanelProps {
 
   onSplit: () => void;
   onExtractSelected: () => void;
+  onOpenSelectionAsWorkspace: () => void;
   onExportReordered: () => void;
 
   splitDownloads: SplitPdfDownload[];
@@ -25,6 +26,7 @@ const ActionsPanel: React.FC<ActionsPanelProps> = ({
   selectedCount,
   onSplit,
   onExtractSelected,
+  onOpenSelectionAsWorkspace,
   onExportReordered,
   splitDownloads,
   subsetDownload,
@@ -37,6 +39,11 @@ const ActionsPanel: React.FC<ActionsPanelProps> = ({
     onExtractSelected();
   };
 
+  const handleOpenSelectionAsWorkspaceClick = () => {
+    if (selectedCount === 0) return;
+    onOpenSelectionAsWorkspace();
+  };
+
   return (
     <div className="card">
       <h2>Tools</h2>
@@ -72,6 +79,20 @@ const ActionsPanel: React.FC<ActionsPanelProps> = ({
           📤 Extract selected ({selectedCount})
         </button>
 
+        <button
+          className="secondary"
+          disabled={disabled || selectedCount === 0}
+          onClick={handleOpenSelectionAsWorkspaceClick}
+          style={{ flex: '1 1 45%' }}
+          title={
+            selectedCount === 0
+              ? 'Select at least one page'
+              : 'Open selected pages as a new unsaved workspace'
+          }
+        >
+          🧩 Open selection as workspace
+        </button>
+
         <button
           className="secondary"
           disabled={disabled}

src/components/HelpDialog.tsx

@@ -45,11 +45,15 @@ const tutorialSteps = [
     body: "Use the checkbox on a page card to select it. Shift-click extends a range. Dragging a selected page moves the whole selection; the copy controls duplicate selected pages into a chosen slot.",
   },
   {
-    title: "4. Save your workspace or export a PDF",
+    title: "4. Extract selected pages or branch into a new workspace",
+    body: "Extract selected pages when you only need a download. Open the selection as a new workspace when you want to continue working on that subset.",
+  },
+  {
+    title: "5. Save your workspace or export a PDF",
     body: "Saving a workspace keeps the current working state in this browser. Exporting creates a new PDF file for download.",
   },
   {
-    title: "5. Use history deliberately",
+    title: "6. Use history deliberately",
     body: "Each workspace operation is stored as a command with label and timestamp. Undo and redo walk through that command history.",
   },
 ];