feat: 全局设置系统 — settings 表、CRUD 路由、主题偏好持久化

src/web/features/settings/index.tsx

@@ -0,0 +1,38 @@
+import { Card, Segmented } from "antd";
+
+import { useSettings } from "../../shared/hooks/use-settings";
+import { parseThemePreference, useThemePreference } from "../../shared/hooks/use-theme-preference";
+
+const THEME_OPTIONS = [
+  { label: "系统", value: "system" },
+  { label: "明亮", value: "light" },
+  { label: "黑暗", value: "dark" },
+] as const;
+
+export function SettingsPage() {
+  const { preference, setPreference } = useThemePreference();
+  const { isUpdating, updateSettings } = useSettings();
+
+  const handleThemeChange = (value: string) => {
+    const theme = parseThemePreference(value);
+    updateSettings(
+      { theme },
+      {
+        onSuccess: () => {
+          setPreference(theme);
+        },
+      },
+    );
+  };
+
+  return (
+    <Card extra={isUpdating ? "保存中..." : undefined} title="主题" type="inner">
+      <Segmented
+        block
+        onChange={(value) => handleThemeChange(value)}
+        options={THEME_OPTIONS.map((option) => ({ label: option.label, value: option.value }))}
+        value={preference}
+      />
+    </Card>
+  );
+}