feat: add Config List page

frontend/src/routes/ConfigList.tsx

@@ -0,0 +1,81 @@
+import { useState, useEffect } from 'react'
+import { useNavigate } from 'react-router-dom'
+import Layout from '../components/Layout'
+import DataTable, { Column } from '../components/DataTable'
+import EntityForm from '../components/EntityForm'
+import Box from '@mui/material/Box'
+import Button from '@mui/material/Button'
+import Chip from '@mui/material/Chip'
+import AddIcon from '@mui/icons-material/Add'
+import { configsApi } from '../api'
+
+interface Config {
+  id: number
+  name: string
+  description: string
+  is_active: boolean
+  created_at: string
+}
+
+const COLUMNS: Column<Config>[] = [
+  { key: 'name', label: 'Name' },
+  { key: 'description', label: 'Description' },
+  { key: 'is_active', label: 'Status', render: (r) => <Chip label={r.is_active ? 'Active' : 'Inactive'} color={r.is_active ? 'success' : 'default'} size="small" /> },
+  { key: 'created_at', label: 'Created', render: (r) => new Date(r.created_at).toLocaleDateString() },
+]
+
+const FIELDS = [
+  { name: 'name', label: 'Name', required: true },
+  { name: 'description', label: 'Description' },
+]
+
+export default function ConfigList() {
+  const [configs, setConfigs] = useState<Config[]>([])
+  const [formOpen, setFormOpen] = useState(false)
+  const [editing, setEditing] = useState<Config | null>(null)
+  const navigate = useNavigate()
+
+  const load = () => configsApi.list().then((r) => setConfigs(r.data))
+  useEffect(() => { load() }, [])
+
+  const handleSubmit = async (values: Record<string, unknown>) => {
+    if (editing) {
+      await configsApi.update(editing.id, values)
+    } else {
+      await configsApi.create(values)
+    }
+    setFormOpen(false)
+    setEditing(null)
+    load()
+  }
+
+  const handleDelete = async (row: Config) => {
+    if (!confirm(`Delete config "${row.name}"?`)) return
+    await configsApi.delete(row.id)
+    load()
+  }
+
+  return (
+    <Layout title="Configurations">
+      <Box sx={{ display: 'flex', justifyContent: 'flex-end', mb: 2 }}>
+        <Button variant="contained" startIcon={<AddIcon />} onClick={() => { setEditing(null); setFormOpen(true) }}>
+          New Config
+        </Button>
+      </Box>
+      <DataTable
+        columns={COLUMNS}
+        rows={configs}
+        onEdit={(row) => { navigate(`/configs/${row.id}`) }}
+        onDelete={handleDelete}
+      />
+      <EntityForm
+        open={formOpen}
+        title={editing ? 'Edit Config' : 'New Config'}
+        fields={FIELDS}
+        initialValues={editing ?? undefined}
+        onClose={() => { setFormOpen(false); setEditing(null) }}
+        onSubmit={handleSubmit}
+      />
+    </Layout>
+  )
+}