feat: Fix flickering in iTerm + scrolling + performance issues.

- Refactors history display using Ink's <Static> component to prevent flickering and improve performance by rendering completed items statically.
- Introduces ConsolePatcher component to capture and display console.log, console.warn, and console.error output within the Ink UI, addressing native handling issues.
- Introduce a new content splitting mechanism to work better for static items. Basically when content gets too long we will now split content into multiple blocks for Gemini messages to ensure that we can statically cache larger pieces of history.

Fixes:
- https://b.corp.google.com/issues/411450097
- https://b.corp.google.com/issues/412716309

1 files changed, 44 insertions, 0 deletions

diff --git a/packages/cli/src/ui/components/HistoryItemDisplay.tsx b/packages/cli/src/ui/components/HistoryItemDisplay.tsx
new file mode 100644
index 00000000..5fb9b32f
--- /dev/null
+++ b/packages/cli/src/ui/components/HistoryItemDisplay.tsx
@@ -0,0 +1,44 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React from 'react';
+import type { HistoryItem } from '../types.js';
+import { UserMessage } from './messages/UserMessage.js';
+import { GeminiMessage } from './messages/GeminiMessage.js';
+import { InfoMessage } from './messages/InfoMessage.js';
+import { ErrorMessage } from './messages/ErrorMessage.js';
+import { ToolGroupMessage } from './messages/ToolGroupMessage.js';
+import { PartListUnion } from '@google/genai';
+import { GeminiMessageContent } from './messages/GeminiMessageContent.js';
+import { Box } from 'ink';
+
+interface HistoryItemDisplayProps {
+  item: HistoryItem;
+  onSubmit: (value: PartListUnion) => void;
+}
+
+export const HistoryItemDisplay: React.FC<HistoryItemDisplayProps> = ({
+  item,
+  onSubmit,
+}) => (
+  <Box flexDirection="column" key={item.id}>
+    {/* Render standard message types */}
+    {item.type === 'user' && <UserMessage text={item.text} />}
+    {item.type === 'gemini' && <GeminiMessage text={item.text} />}
+    {item.type === 'gemini_content' && (
+      <GeminiMessageContent text={item.text} />
+    )}
+    {item.type === 'info' && <InfoMessage text={item.text} />}
+    {item.type === 'error' && <ErrorMessage text={item.text} />}
+    {item.type === 'tool_group' && (
+      <ToolGroupMessage
+        toolCalls={item.tools}
+        groupId={item.id}
+        onSubmit={onSubmit}
+      />
+    )}
+  </Box>
+);