feat(workspace): intelligent multi-line clipboard paste with markdown prefix & indentation parsing

frontend/src/features/workspace/DocumentEditor.tsx

@@ -544,6 +544,29 @@ export const DocumentEditor: React.FC<DocumentEditorProps> = ({
     [docId, canEdit]
   );
 
+  const handleInsertBlocks = useCallback(
+    (afterBlockId: string, updatedCurrentBlock: DocumentBlock, newBlocks: DocumentBlock[]) => {
+      if (!canEdit) return;
+      setBlocks((prev) => {
+        const next = [...prev];
+        const idx = next.findIndex((b) => b.id === afterBlockId);
+        if (idx >= 0) {
+          next[idx] = updatedCurrentBlock;
+          next.splice(idx + 1, 0, ...newBlocks);
+        } else {
+          next.push(updatedCurrentBlock, ...newBlocks);
+        }
+        const normalized = ensureNonEmptyBlocks(docId, next);
+        currentBlocksRef.current = normalized;
+        return normalized;
+      });
+      window.setTimeout(() => {
+        executeAutoSave(true);
+      }, 50);
+    },
+    [docId, canEdit, executeAutoSave]
+  );
+
   const handleDeleteBlock = useCallback(
     (blockId: string) => {
       if (!canEdit) return;
@@ -947,6 +970,7 @@ export const DocumentEditor: React.FC<DocumentEditorProps> = ({
                 onUpdateBlock={handleUpdateBlock}
                 onUpdateBlocks={handleUpdateBlocks}
                 onCreateBlock={handleCreateBlock}
+                onInsertBlocks={handleInsertBlocks}
                 onDeleteBlock={handleDeleteBlock}
                 onMoveBlock={handleMoveBlock}
                 onOpenTask={onOpenTask}
@@ -1082,6 +1106,7 @@ export const DocumentEditor: React.FC<DocumentEditorProps> = ({
               onUpdateBlock={handleUpdateBlock}
               onUpdateBlocks={handleUpdateBlocks}
               onCreateBlock={handleCreateBlock}
+              onInsertBlocks={handleInsertBlocks}
               onDeleteBlock={handleDeleteBlock}
               onMoveBlock={handleMoveBlock}
               onOpenTask={onOpenTask}