feat(cli): 支持 Markdown 引用块渲染并改进表格显示

- 新增 BlockquoteRenderer 组件，使用 ▎ 竖条和斜体样式渲染引用块
- 在 markdown 解析器和增量处理器中新增对引用块语法的识别与处理
- 重构表格渲染器，采用三层宽度策略（理想/收缩/强制断词）并支持多行单元格换行
- 当终端过窄或行数过多时，表格自动降级为垂直键值对格式以提升可读性
- 移除代码块中对 markdown 语言的递归解析，简化处理逻辑

Author: echoVic

packages/cli/src/ui/components/BlockquoteRenderer.tsx

@@ -0,0 +1,43 @@
+/**
+ * Blockquote 渲染器
+ * 使用 ▎ (U+258E) 竖条 + italic 样式显示引用内容
+ */
+
+import { Box, Text } from 'ink';
+import React from 'react';
+import { useTheme } from '../../store/selectors/index.js';
+import { InlineRenderer } from './InlineRenderer.js';
+
+interface BlockquoteRendererProps {
+  lines: string[];
+  level: number;
+}
+
+const BLOCKQUOTE_BAR = '\u258e'; // ▎ left one-quarter block
+
+export const BlockquoteRenderer: React.FC<BlockquoteRendererProps> = React.memo(
+  ({ lines, level }) => {
+    const theme = useTheme();
+    const bar = BLOCKQUOTE_BAR.repeat(level);
+
+    return (
+      <Box flexDirection="column">
+        {lines.map((line, i) => {
+          if (line.trim() === '') {
+            return <Box key={i} height={1} />;
+          }
+          return (
+            <Box key={i} flexDirection="row">
+              <Text dimColor color={theme.colors.text.muted}>
+                {bar}{' '}
+              </Text>
+              <Text italic wrap="wrap">
+                <InlineRenderer text={line} />
+              </Text>
+            </Box>
+          );
+        })}
+      </Box>
+    );
+  }
+);

packages/cli/src/ui/components/MessageRenderer.tsx

@@ -22,6 +22,7 @@ import {
 } from '../utils/markdownParser.js';
 import { CodeHighlighter } from './CodeHighlighter.js';
 import { DiffRenderer } from './DiffRenderer.js';
+import { BlockquoteRenderer } from './BlockquoteRenderer.js';
 import { InlineRenderer } from './InlineRenderer.js';
 import { ListItem } from './ListItem.js';
 import { TableRenderer } from './TableRenderer.js';
@@ -729,6 +730,11 @@ export const MessageRenderer: React.FC<MessageRendererProps> = React.memo(
                   />
                 ) : block.type === 'command-message' ? (
                   <CommandMessage content={block.content} />
+                ) : block.type === 'blockquote' && block.blockquoteLines ? (
+                  <BlockquoteRenderer
+                    lines={block.blockquoteLines}
+                    level={block.blockquoteLevel || 1}
+                  />
                 ) : (
                   <TextBlock content={block.content} />
                 )}