feat(client): 节点列表防误触 — 已连接时切换节点先弹确认

未连接(off)点节点直接选→跳连接页(无破坏性,不弹框);已连接/连接中点其他
节点会断开重连,先弹确认框(标题含目标节点名),取消则维持当前连接。新增
nodeSwitchTitle/Body/Confirm 三条文案 + node_connect_confirm_test 覆盖 off/on 两路。

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

client/lib/screens/nodes_page.dart

@@ -49,6 +49,43 @@ class _NodesPageState extends ConsumerState<NodesPage> {
     widget.onPicked();
   }
 
+  // 点节点:未连接(off)直接选→跳连接页,无破坏性;已连接/连接中切换会断开重连,
+  // 弹确认防误触(误碰节点把当前连接切走)。
+  void _onTapNode(Node n) {
+    final phase = ref.read(connectionProvider).phase;
+    if (phase == VpnPhase.off) {
+      _pick(n.code);
+      return;
+    }
+    _confirmSwitch(n);
+  }
+
+  Future<void> _confirmSwitch(Node n) async {
+    final c = context.pangolin;
+    final t = ref.read(appTextProvider);
+    final ok = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        backgroundColor: c.surface,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(PangolinRadius.xl)),
+        title: Text(t.nodeSwitchTitle(n.localizedName(t.lang)),
+            style: PangolinText.body.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
+        content: Text(t.nodeSwitchBody, style: PangolinText.sm.copyWith(color: c.fg2, height: 1.5)),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx, false),
+            child: Text(t.devCancel, style: PangolinText.sm.copyWith(color: c.fg2, fontWeight: FontWeight.w600)),
+          ),
+          TextButton(
+            onPressed: () => Navigator.pop(ctx, true),
+            child: Text(t.nodeSwitchConfirm, style: PangolinText.sm.copyWith(color: c.accent, fontWeight: FontWeight.w700)),
+          ),
+        ],
+      ),
+    );
+    if (ok == true) _pick(n.code);
+  }
+
   List<Node> _filtered(List<Node> nodes) {
     if (_q.trim().isEmpty) return nodes;
     final q = _q.toLowerCase();
@@ -95,7 +132,7 @@ class _NodesPageState extends ConsumerState<NodesPage> {
             childAspectRatio: 4.4,
             children: [
               for (final n in nodes)
-                _NodeGridTile(node: n, lang: t.lang, active: !smart && n.code == selected, onTap: () => _pick(n.code)),
+                _NodeGridTile(node: n, lang: t.lang, active: !smart && n.code == selected, onTap: () => _onTapNode(n)),
             ],
           ),
         ],
@@ -133,7 +170,7 @@ class _NodesPageState extends ConsumerState<NodesPage> {
                     node: nodes[i],
                     lang: t.lang,
                     active: !smart && nodes[i].code == selected,
-                    onTap: () => _pick(nodes[i].code),
+                    onTap: () => _onTapNode(nodes[i]),
                   ),
                   if (i < nodes.length - 1) Divider(height: 1, thickness: 1, color: c.border),
                 ],