fix(client): 补提交 stats-overhaul 漏掉的 account_api/kernel_process WIP

同 device_usage:account_api.dart(deviceUsage/usage 方法)、kernel_process.dart
及对应测试一直未提交,本地有→analyze/test 过,但不在 git→Windows 构建报
「deviceUsage isn't defined」。补齐使提交树自洽可构建。
孤儿组件 device_stat_row/metric_card 已无人引用,不提交。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/test/bridge/kernel_process_test.dart

@@ -240,6 +240,53 @@ void main() {
     });
   });
 
+  // ── URLTest 延迟/组名提取 ─────────────────────────────────────
+  group('URLTest extraction', () {
+    final proxies = <String, dynamic>{
+      'proxies': {
+        'auto': {
+          'type': 'URLTest',
+          'all': ['reality-out', 'hy2-out'],
+        },
+        'reality-out': {
+          'type': 'Vless',
+          'history': [
+            {'time': 't1', 'delay': 30},
+            {'time': 't2', 'delay': 42},
+          ],
+        },
+        'hy2-out': {
+          'type': 'Hysteria2',
+          'history': [
+            {'time': 't1', 'delay': 88},
+          ],
+        },
+        'direct': {'type': 'Direct'},
+      },
+    };
+
+    test('extractUrltestGroups 返回 URLTest/Fallback 组名', () {
+      expect(ClashApiClient.extractUrltestGroups(proxies), ['auto']);
+    });
+
+    test('extractUrltestResults 取成员最新 history delay', () {
+      final r = ClashApiClient.extractUrltestResults(proxies);
+      final byTag = {for (final e in r) e.tag: e.delayMs};
+      expect(byTag['reality-out'], 42); // history.last
+      expect(byTag['hy2-out'], 88);
+    });
+
+    test('无 URLTest 组时返回空', () {
+      final empty = {
+        'proxies': {
+          'direct': {'type': 'Direct'},
+        },
+      };
+      expect(ClashApiClient.extractUrltestGroups(empty), isEmpty);
+      expect(ClashApiClient.extractUrltestResults(empty), isEmpty);
+    });
+  });
+
   // ── 2. 随机生成工具函数 ───────────────────────────────────────
   group('Port and secret generators', () {
     test('generateClashApiPort is in range 49152–65535', () {