feat: add Layout and ProtectedRoute components

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/Layout.tsx

@@ -0,0 +1,65 @@
+import { ReactNode } from 'react'
+import { useNavigate, useLocation } from 'react-router-dom'
+import Box from '@mui/material/Box'
+import Drawer from '@mui/material/Drawer'
+import List from '@mui/material/List'
+import ListItemButton from '@mui/material/ListItemButton'
+import ListItemIcon from '@mui/material/ListItemIcon'
+import ListItemText from '@mui/material/ListItemText'
+import Typography from '@mui/material/Typography'
+import Divider from '@mui/material/Divider'
+import IconButton from '@mui/material/IconButton'
+import Tooltip from '@mui/material/Tooltip'
+import DnsIcon from '@mui/icons-material/Dns'
+import LogoutIcon from '@mui/icons-material/Logout'
+import { useAuth } from '../store/auth'
+
+const DRAWER_WIDTH = 240
+
+interface Props { children: ReactNode; title: string }
+
+export default function Layout({ children, title }: Props) {
+  const navigate = useNavigate()
+  const location = useLocation()
+  const { user, logout } = useAuth()
+
+  return (
+    <Box sx={{ display: 'flex', minHeight: '100vh' }}>
+      <Drawer variant="permanent" sx={{ width: DRAWER_WIDTH, '& .MuiDrawer-paper': { width: DRAWER_WIDTH } }}>
+        <Box sx={{ px: 2, py: 3 }}>
+          <Typography variant="h6" sx={{ color: '#e2e8f0', fontWeight: 700, letterSpacing: 1 }}>
+            Shorefront
+          </Typography>
+          <Typography variant="caption" sx={{ color: '#94a3b8' }}>
+            Shorewall Manager
+          </Typography>
+        </Box>
+        <Divider sx={{ borderColor: '#2d3748' }} />
+        <List sx={{ flex: 1 }}>
+          <ListItemButton
+            selected={location.pathname.startsWith('/configs')}
+            onClick={() => navigate('/configs')}
+            sx={{ '&.Mui-selected': { backgroundColor: '#2d3748' }, '&:hover': { backgroundColor: '#2d3748' } }}
+          >
+            <ListItemIcon sx={{ color: '#94a3b8', minWidth: 36 }}><DnsIcon fontSize="small" /></ListItemIcon>
+            <ListItemText primary="Configurations" primaryTypographyProps={{ sx: { color: '#e2e8f0', fontSize: 14 } }} />
+          </ListItemButton>
+        </List>
+        <Divider sx={{ borderColor: '#2d3748' }} />
+        <Box sx={{ px: 2, py: 2, display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
+          <Typography variant="caption" sx={{ color: '#94a3b8' }}>{user?.username}</Typography>
+          <Tooltip title="Logout">
+            <IconButton onClick={logout} size="small" sx={{ color: '#94a3b8' }}><LogoutIcon fontSize="small" /></IconButton>
+          </Tooltip>
+        </Box>
+      </Drawer>
+
+      <Box component="main" sx={{ flex: 1, bgcolor: 'background.default' }}>
+        <Box sx={{ px: 4, py: 3, bgcolor: 'white', borderBottom: '1px solid #e2e8f0' }}>
+          <Typography variant="h5" fontWeight={600}>{title}</Typography>
+        </Box>
+        <Box sx={{ p: 4 }}>{children}</Box>
+      </Box>
+    </Box>
+  )
+}