feat: 对齐常驻商城与七鱼客服交互

- 同步商城 H5 登录态与原生 token
- 完善商城/原生 tab 切换、动画及返回交互
- 修复七鱼客服键盘避让和状态栏恢复
- 调整开屏跳过按钮与登录入口交互

lib/features/mall/application/mall_entry_controller.dart

@@ -0,0 +1,60 @@
+import 'package:flutter/material.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+import '../../web/application/mall_web_host_controller.dart';
+import 'mall_tab_config.dart';
+
+enum MallEntryOpenResult { opened, unavailable, failed, alreadyOpening }
+
+class MallEntryController {
+  MallEntryController(this._ref);
+
+  final Ref _ref;
+  bool _opening = false;
+
+  Future<MallEntryOpenResult> open(
+    BuildContext context, {
+    MallTabConfig? initialConfig,
+  }) async {
+    if (_opening) return MallEntryOpenResult.alreadyOpening;
+    _opening = true;
+    try {
+      var config = initialConfig;
+      if (config?.isVisible != true) {
+        config = await _ref.read(mallTabConfigProvider.notifier).ensureLoaded();
+      }
+      if (config?.isVisible != true || !context.mounted) {
+        return MallEntryOpenResult.unavailable;
+      }
+      final clickId = await _ref
+          .read(mallTabConfigProvider.notifier)
+          .recordClick();
+      if (clickId == null || !context.mounted) {
+        return MallEntryOpenResult.unavailable;
+      }
+      _ref
+          .read(mallClickAttributionProvider.notifier)
+          .state = MallClickAttribution(
+        adId: config!.adId,
+        trackingId: config.trackingId,
+        clickId: clickId,
+      );
+      final uri = config.attributedUri(
+        clickId: clickId,
+        isDark: Theme.of(context).brightness == Brightness.dark,
+      );
+      if (uri == null) return MallEntryOpenResult.unavailable;
+      // The bottom mall entry is always resident. Server open-mode metadata is
+      // still retained for attribution, while explicit links inside H5 decide
+      // their own external handoff through the WebView navigation policy.
+      MallWebHostController.instance.open(uri);
+      return MallEntryOpenResult.opened;
+    } catch (_) {
+      return MallEntryOpenResult.failed;
+    } finally {
+      _opening = false;
+    }
+  }
+}
+
+final mallEntryControllerProvider = Provider((ref) => MallEntryController(ref));