feat(outliner): indent and outdent entire subtree with all children on Tab and Shift+Tab

frontend/src/features/workspace/OutlinerTree.tsx

@@ -13,6 +13,7 @@ export interface OutlinerTreeProps {
   remoteCursors?: Record<string, RemoteCursor>;
   sendCursorMoved?: (blockId: string | null, selectionStart?: number, selectionEnd?: number) => void;
   onUpdateBlock: (updated: DocumentBlock, immediate?: boolean) => void;
+  onUpdateBlocks?: (updated: DocumentBlock[]) => void;
   onCreateBlock: (newBlock: DocumentBlock, afterBlockId?: string) => void;
   onDeleteBlock: (blockId: string) => void;
   onMoveBlock: (blockId: string, newIndex: number, level?: number) => void;
@@ -34,6 +35,7 @@ export const OutlinerTree: React.FC<OutlinerTreeProps> = ({
   remoteCursors,
   sendCursorMoved,
   onUpdateBlock,
+  onUpdateBlocks,
   onCreateBlock,
   onDeleteBlock,
   onMoveBlock,
@@ -172,7 +174,7 @@ export const OutlinerTree: React.FC<OutlinerTreeProps> = ({
     }
 
     return result;
-  }, [blocks]);
+  }, [blocks, levelOffset]);
 
   const handleCreateBlockBelow = useCallback(
     (afterBlockId: string, _currentContent: string) => {
@@ -241,9 +243,9 @@ export const OutlinerTree: React.FC<OutlinerTreeProps> = ({
       const current = blocks[idx];
       const currentLevel = Math.max(0, current.level || 0);
       const prevLevel = idx > 0 ? Math.max(0, blocks[idx - 1].level || 0) : 0;
-      const maxLevel = idx === 0 ? 0 : prevLevel + 1;
-
       const minLevel = levelOffset || 0;
+      const maxLevel = idx === 0 ? minLevel : prevLevel + 1;
+
       const nextLevel =
         delta === 1
           ? Math.min(maxLevel, currentLevel + 1)
@@ -251,15 +253,38 @@ export const OutlinerTree: React.FC<OutlinerTreeProps> = ({
 
       if (nextLevel === currentLevel) return;
 
-      onUpdateBlock(
-        {
-          ...current,
-          level: nextLevel,
-        },
-        true
-      );
+      const actualDelta = nextLevel - currentLevel;
+
+      // Find all contiguous children / descendants:
+      // contiguous blocks with level > currentLevel
+      let count = 1;
+      for (let i = idx + 1; i < blocks.length; i++) {
+        if (Math.max(0, blocks[i].level || 0) > currentLevel) {
+          count++;
+        } else {
+          break;
+        }
+      }
+
+      const updatedBlocks: DocumentBlock[] = [];
+      for (let i = idx; i < idx + count; i++) {
+        const b = blocks[i];
+        const newLvl = Math.max(minLevel, (b.level || 0) + actualDelta);
+        updatedBlocks.push({
+          ...b,
+          level: newLvl,
+        });
+      }
+
+      if (onUpdateBlocks) {
+        onUpdateBlocks(updatedBlocks);
+      } else {
+        for (const b of updatedBlocks) {
+          onUpdateBlock(b, true);
+        }
+      }
     },
-    [blocks, canEdit, onUpdateBlock]
+    [blocks, canEdit, levelOffset, onUpdateBlock, onUpdateBlocks]
   );
 
   const handleNavigateFocus = useCallback(