refactor: 移除顶部栏，设置按钮移至底部栏右侧，StatusBar 全面改 MUI Table

- StatusBar: 全 MUI Table 布局，左侧状态/Provider/Token，右侧版本+设置
- Header: 已删除(功能合并到 StatusBar)
- App.tsx: 移除 Header 引用

src/App.tsx

@@ -9,7 +9,6 @@
 
 import { ThemeProvider, CssBaseline } from '@mui/material';
 import { useEffect } from 'react';
-import { Header } from '@renderer/components/layout/Header';
 import { Sidebar } from '@renderer/components/layout/Sidebar';
 import { DetailPanel } from '@renderer/components/layout/DetailPanel';
 import { StatusBar } from '@renderer/components/layout/StatusBar';
@@ -55,7 +54,6 @@ export default function App(): React.JSX.Element {
         className="h-screen w-screen flex flex-col overflow-hidden select-none"
         style={{ background: muiTheme.palette.background.default, color: muiTheme.palette.text.primary }}
       >
-        <Header />
         <div className="flex-1 flex overflow-hidden min-h-0">
           <Sidebar />
           <ChatPanel />

src/components/layout/Header.tsx

@@ -1,44 +0,0 @@
-/**
- * Header — 标题栏
- *
- * Logo + 会话标题 + 设置按钮。
- */
-
-import { Box, IconButton, Tooltip, Stack, Typography } from '@mui/material';
-import { Settings } from 'lucide-react';
-import { useUIStore } from '@renderer/stores/ui-store';
-import { useSessionStore } from '@renderer/stores/session-store';
-
-type WebkitCSS = React.CSSProperties & { WebkitAppRegion?: string };
-
-export function Header(): React.JSX.Element {
-  const openSettings = useUIStore((s) => s.openSettings);
-  const currentSessionId = useSessionStore((s) => s.currentSessionId);
-  const sessions = useSessionStore((s) => s.sessions);
-  const currentSession = sessions.find((s) => s.id === currentSessionId);
-
-  return (
-    <header
-      style={{
-        flexShrink: 0, display: 'flex', alignItems: 'center', justifyContent: 'space-between',
-        padding: '0 16px', height: 40, userSelect: 'none',
-        background: 'var(--bg-secondary)', borderBottom: '1px solid var(--border-color)',
-        WebkitAppRegion: 'drag',
-      } as WebkitCSS}
-    >
-      <Stack direction="row" spacing={1} alignItems="center" sx={{ minWidth: 0 }}>
-        <Box component="img" src="./assets/logo.png" alt="Metona" sx={{ width: 20, height: 20, borderRadius: 0.5 }} />
-        <Typography variant="body2" sx={{ fontWeight: 600, color: 'primary.main', fontSize: 13 }}>MetonaAI</Typography>
-        {currentSession && (
-          <>
-            <Typography variant="body2" sx={{ color: 'divider' }}>·</Typography>
-            <Typography variant="caption" sx={{ color: 'text.secondary', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{currentSession.title}</Typography>
-          </>
-        )}
-      </Stack>
-      <Stack direction="row" spacing={0.5} sx={{ WebkitAppRegion: 'no-drag' } as WebkitCSS}>
-        <Tooltip title="设置 (Ctrl+,)"><IconButton size="small" onClick={openSettings} sx={{ color: 'text.secondary' }}><Settings size={14} /></IconButton></Tooltip>
-      </Stack>
-    </header>
-  );
-}

src/components/layout/StatusBar.tsx

@@ -1,11 +1,13 @@
 /**
  * StatusBar — 底部状态栏
  *
- * 显示 Agent 状态指示灯、Provider 名称、Token 统计、版本号。
+ * 完全使用 MUI 组件：Table 展示状态/Provider/Token，右侧设置按钮。
  */
 
-import { Box, Typography, Stack, Chip } from '@mui/material';
+import { Box, Typography, IconButton, Tooltip, Table, TableBody, TableRow, TableCell } from '@mui/material';
+import { Settings } from 'lucide-react';
 import { useAgentStore } from '@renderer/stores/agent-store';
+import { useUIStore } from '@renderer/stores/ui-store';
 import { AGENT_STATUS_COLORS, AGENT_STATUS_LABELS, PROVIDER_LABELS } from '@renderer/lib/constants';
 import { formatTokens } from '@renderer/lib/formatters';
 
@@ -14,42 +16,63 @@ export function StatusBar(): React.JSX.Element {
   const provider = useAgentStore((s) => s.provider);
   const model = useAgentStore((s) => s.model);
   const tokenUsage = useAgentStore((s) => s.tokenUsage);
+  const openSettings = useUIStore((s) => s.openSettings);
 
   return (
     <Box
       component="footer"
       sx={{
-        flexShrink: 0, display: 'flex', alignItems: 'center', justifyContent: 'space-between',
-        px: 2, height: 24, bgcolor: 'background.paper', borderTop: 1, borderColor: 'divider', userSelect: 'none',
+        flexShrink: 0, display: 'flex', alignItems: 'center',
+        px: 1.5, height: 28, bgcolor: 'background.paper',
+        borderTop: 1, borderColor: 'divider', userSelect: 'none',
       }}
     >
-      <Stack direction="row" spacing={1.5} alignItems="center">
-        <Stack direction="row" spacing={0.75} alignItems="center">
+      {/* 左侧：状态信息表格 */}
+      <Table size="small" sx={{
+        flex: 1, width: 'auto',
+        '& .MuiTableCell-root': { border: 0, py: 0, px: 1, fontSize: 10, whiteSpace: 'nowrap' },
+      }}>
+        <TableBody>
+          <TableRow>
+            <TableCell sx={{ width: 'auto', py: 0, px: 1 }}>
+              <Box sx={{ display: 'flex', alignItems: 'center', gap: 0.75 }}>
                 <Box
                   sx={{
-              width: 8, height: 8, borderRadius: '50%', flexShrink: 0,
+                    width: 7, height: 7, borderRadius: '50%', flexShrink: 0,
                     bgcolor: AGENT_STATUS_COLORS[agentStatus],
                     animation: (agentStatus === 'thinking' || agentStatus === 'executing') ? 'pulse 2s infinite' : 'none',
                   }}
                 />
-          <Typography variant="caption" sx={{ color: 'text.secondary', fontSize: 11, lineHeight: 1 }}>
+                <Typography variant="caption" sx={{ color: 'text.secondary', fontSize: 10, lineHeight: 1 }}>
                   {AGENT_STATUS_LABELS[agentStatus]}
                 </Typography>
-        </Stack>
-        <Typography variant="caption" sx={{ color: 'divider' }}>|</Typography>
-        <Typography variant="caption" sx={{ color: 'text.secondary', fontSize: 11 }}>
+              </Box>
+            </TableCell>
+            <TableCell sx={{ color: 'divider', width: 1, p: 0 }}>|</TableCell>
+            <TableCell sx={{ color: 'text.secondary', fontSize: 10 }}>
               {PROVIDER_LABELS[provider] ?? provider} {model}
-        </Typography>
-      </Stack>
-
-      <Stack direction="row" spacing={1.5} alignItems="center">
+            </TableCell>
             {tokenUsage.totalTokens > 0 && (
-          <Typography variant="caption" sx={{ color: 'text.secondary', fontSize: 11 }}>
-            Tokens: {formatTokens(tokenUsage.inputTokens)}↓ {formatTokens(tokenUsage.outputTokens)}↑
-          </Typography>
+              <>
+                <TableCell sx={{ color: 'divider', width: 1, p: 0 }}>|</TableCell>
+                <TableCell sx={{ fontFamily: 'monospace', color: 'text.secondary', fontSize: 10 }}>
+                  {formatTokens(tokenUsage.inputTokens)}↓ {formatTokens(tokenUsage.outputTokens)}↑
+                </TableCell>
+              </>
             )}
-        <Typography variant="caption" sx={{ color: 'text.secondary', fontSize: 11 }}>MetonaAI v0.1.0</Typography>
-      </Stack>
+          </TableRow>
+        </TableBody>
+      </Table>
+
+      {/* 右侧：版本 + 设置 */}
+      <Box sx={{ display: 'flex', alignItems: 'center', gap: 0.5, flexShrink: 0 }}>
+        <Typography variant="caption" sx={{ color: 'text.disabled', fontSize: 9 }}>v0.1.0</Typography>
+        <Tooltip title="设置 (Ctrl+,)">
+          <IconButton size="small" onClick={openSettings} sx={{ color: 'text.secondary', width: 24, height: 24 }}>
+            <Settings size={12} />
+          </IconButton>
+        </Tooltip>
+      </Box>
     </Box>
   );
 }