Add demo mode factory reset

- Align the backend seeded default surgery template with the report editor's default report content.

- Add backend demo defaults for the default template, Kimi provider, and Xunfei speech proxy configuration.

- Change system reset into a super-admin demo mode factory reset that clears reports, audit logs, files, custom templates, and non-default users.

- Keep only the default admin, manager, doctor, and default surgery template after demo reset.

- Replace the old local-only reset all data button with a two-confirmation backend reset flow.

- Add tests covering demo default alignment and database-backed demo reset behavior.

- Update docs to describe demo mode reset semantics and production credential cautions.

src/pages/SystemSettings.tsx

@@ -204,44 +204,22 @@ export default function SystemSettings() {
   };
 
   const resetToDefault = async () => {
-    if (window.confirm('确定要恢复系统设置出厂设置吗？所有自定义配置将被清除。')) {
-      const defaultSettings: ISystemSettings & { frameMode?: 'uniform' | 'keep' } = {
-        frameCount: 12,
-        framePositions: [7.9, 9.3, 46.2, 49.1, 63.9, 64.8, 68.8, 73.7, 80.2, 85.0, 96.3, 98.6],
-        defaultTemplate: templates[0]?.id || '',
-        frameMode: 'keep',
-        activeAiProvider: 'kimi',
-        aiProviders: { ...DEFAULT_AI_PROVIDERS },
-        autoInsertFrames: true,
-        autoInsertDelay: 1,
-        autoInsertFrameIndices: [0, 2, 4, 6, 8, 10],
-        xfSpeechConfig: { appId: '', apiKey: '', apiSecret: '' }
-      };
-      try {
-        const resetSettings = await resetSystemSettings();
-        const normalized = normalizeSettings(resetSettings, templates);
-        setSettings(normalized);
-        storage.set('systemSettings', normalized);
-      } catch (error) {
-        if (!isLocalFallbackEnabled()) {
-          alert(`重置失败: ${(error as Error).message}`);
-          return;
-        }
-        console.warn('Reset settings API failed, keeping local compatibility path.', error);
-        setSettings(defaultSettings);
-        storage.set('systemSettings', defaultSettings);
-      }
-    }
-  };
+    const firstConfirm = window.confirm('确定要恢复演示出厂设置吗？这会清空报告、审计日志、自定义模板和非默认用户，并恢复默认演示账号、模板、AI/语音配置。');
+    if (!firstConfirm) return;
 
-  const resetAllData = () => {
-    if (!isLocalFallbackEnabled()) {
-      alert('生产模式下仅允许清理当前浏览器缓存，请联系管理员执行后端数据维护。');
-      return;
-    }
-    if (window.confirm('确定要重置全部数据吗？这将清除所有报告、模板和用户设置。')) {
+    const secondConfirm = window.confirm('请再次确认：该操作会重置当前后端演示数据，且无法从页面撤销。是否继续？');
+    if (!secondConfirm) return;
+
+    try {
+      const resetSettings = await resetSystemSettings();
+      const normalized = normalizeSettings(resetSettings, templates);
+      setSettings(normalized);
+      storage.set('systemSettings', normalized);
       localStorage.clear();
+      sessionStorage.clear();
       window.location.reload();
+    } catch (error) {
+      alert(`恢复演示出厂设置失败: ${(error as Error).message}`);
     }
   };
 
@@ -592,14 +570,7 @@ export default function SystemSettings() {
                   onClick={resetToDefault}
                   className="text-xs font-bold text-red-500 hover:text-red-600 transition-colors uppercase tracking-wider"
                 >
-                  恢复系统设置出厂设置
-                </button>
-                <button
-                  type="button"
-                  onClick={resetAllData}
-                  className="text-xs font-bold text-red-500 hover:text-red-600 transition-colors uppercase tracking-wider"
-                >
-                  重置全部数据
+                  恢复演示出厂设置
                 </button>
               </div>
             )}