refactor(layout): 统一页面边距管理，移除 Container 限制

- layoutConfig.js: 新增 LAYOUT_PADDING 常量 { base: 4, md: 6, lg: '80px' }
- MainLayout.js: 在 Outlet 容器上统一应用 px={LAYOUT_PADDING.x}
- HomeNavbar.js: 边距从 lg:8 改为 lg:'80px'，与内容区对齐
- AppFooter.js: 移除 Container，边距改为 lg:'80px'

页面组件清理（移除冗余的 px/Container）：
- Company, Community, Center, Profile, Settings
- ValueForum, DataBrowser, LimitAnalyse, StockOverview, Concept

特殊处理：
- CompanyHeader: 使用负边距实现全宽背景
- Concept Hero: 使用负边距实现全宽背景

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/views/Company/components/CompanyHeader/index.tsx

@@ -7,6 +7,7 @@ import { Box, Flex, HStack, VStack, Text } from '@chakra-ui/react';
 import { AutoComplete, Input, Spin } from 'antd';
 import { SearchOutlined } from '@ant-design/icons';
 import { useStockSearch } from '@hooks/useStockSearch';
+import { LAYOUT_PADDING } from '@/layouts/config/layoutConfig';
 import { THEME } from '../../config';
 import { FUI_COLORS, FUI_GLOW } from '../../theme/fui';
 import type { CompanyHeaderProps, StockSearchResult } from '../../types';
@@ -115,17 +116,17 @@ SearchBox.displayName = 'SearchBox';
 const CompanyHeader: React.FC<CompanyHeaderProps> = memo(({ onStockChange }) => (
   <Box
     position="relative"
-    bg={FUI_COLORS.bg.primary}
-    borderBottom="1px solid"
-    borderColor={FUI_COLORS.line.default}
-    px={6}
-    py={4}
+    border="1px solid"
+    borderRadius="8px"
+    sx={{
+      bg: FUI_COLORS.bg.primary,
+      borderColor: FUI_COLORS.line.default,
+      padding: '20px 20px',
+    }}
   >
     <Flex
       position="relative"
       zIndex={1}
-      maxW="container.xl"
-      mx="auto"
       justify="space-between"
       align="center"
     >