feat(cli): core logic for dense tool output and history merging

- Update useGeminiStream to detect dense tool batches (non-verbose, non-shell).
- Update useHistoryManager to merge consecutive tool_group items into a single history entry.
- Add unit tests for history manager merging logic.

packages/cli/src/ui/hooks/useGeminiStream.ts

@@ -80,6 +80,8 @@ import { useSessionStats } from '../contexts/SessionContext.js';
 import { useKeypress } from './useKeypress.js';
 import type { LoadedSettings } from '../../config/settings.js';
 
+import { isShellTool } from '../components/messages/ToolShared.js';
+
 type ToolResponseWithParts = ToolCallResponseInfo & {
   llmContent?: PartListUnion;
 };
@@ -356,6 +358,8 @@ export const useGeminiStream = (
     addItem,
   ]);
 
+  const isVerboseMode = settings.merged.output?.verbosity === 'verbose';
+
   const pendingToolGroupItems = useMemo((): HistoryItemWithoutId[] => {
     const remainingTools = toolCalls.filter(
       (tc) => !pushedToolCallIds.has(tc.request.callId),
@@ -375,6 +379,14 @@ export const useGeminiStream = (
     // Always show a bottom border slice if we have ANY tools in the batch
     // and we haven't finished pushing the whole batch to history yet.
     // Once all tools are terminal and pushed, the last history item handles the closing border.
+    // NOTE: In dense mode, we skip this if there are no shell tools (which require boxes).
+    const requiresBoxLayout =
+      isVerboseMode || toolCalls.some((tc) => isShellTool(tc.request.name));
+
+    if (!requiresBoxLayout) {
+      return items;
+    }
+
     const allTerminal =
       toolCalls.length > 0 &&
       toolCalls.every(
@@ -419,7 +431,7 @@ export const useGeminiStream = (
     }
 
     return items;
-  }, [toolCalls, pushedToolCallIds]);
+  }, [toolCalls, pushedToolCallIds, isVerboseMode]);
 
   const activeToolPtyId = useMemo(() => {
     const executingShellTool = toolCalls.find(

packages/cli/src/ui/hooks/useHistoryManager.test.ts

@@ -323,4 +323,29 @@ describe('useHistoryManager', () => {
     expect(thirdItem.type).toBe('tool_group');
     expect(thirdItem.tools).toHaveLength(1);
   });
+
+  it('should update borderBottom when merging tool groups', () => {
+    const { result } = renderHook(() => useHistory());
+    const timestamp = Date.now();
+    const toolGroup1: HistoryItemWithoutId = {
+      type: 'tool_group',
+      tools: [{ callId: '1', name: 'tool-a' } as IndividualToolCallDisplay],
+      borderBottom: false,
+    };
+    const toolGroup2: HistoryItemWithoutId = {
+      type: 'tool_group',
+      tools: [{ callId: '2', name: 'tool-b' } as IndividualToolCallDisplay],
+      borderBottom: true,
+    };
+
+    act(() => {
+      result.current.addItem(toolGroup1, timestamp);
+      result.current.addItem(toolGroup2, timestamp + 1);
+    });
+
+    expect(result.current.history).toHaveLength(1);
+    const mergedItem = result.current.history[0] as HistoryItemToolGroup;
+    expect(mergedItem.tools).toHaveLength(2);
+    expect(mergedItem.borderBottom).toBe(true);
+  });
 });

packages/cli/src/ui/hooks/useHistoryManager.ts

@@ -78,6 +78,7 @@ export function useHistory({
           const updatedLastItem: HistoryItem = {
             ...lastItem,
             tools: [...lastItem.tools, ...newItem.tools],
+            borderBottom: newItem.borderBottom,
           };
           return [...prevHistory.slice(0, -1), updatedLastItem];
         }