fix(ui): SegSwitch 用 FittedBox(scaleDown) 防窄容器截断文字

添加规则弹层的动作段选(Direct/Tunnel/Reject)在窄弹层里被 icon+文字挤到 ellipsis 截断
成「Dire…/Tun…/Reje…」。改:段内容包 FittedBox(scaleDown)——放得下原样(宽段选/goldens
不变),放不下整体等比缩放而非截断;padding 16→12 留余量。flutter test 265/265 无 golden 回归。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A79VtQA1BwTuQN1ThpvYpo

client/lib/widgets/seg_switch.dart

@@ -49,30 +49,32 @@ class SegSwitch extends StatelessWidget {
       child: AnimatedContainer(
         duration: const Duration(milliseconds: 140),
         curve: Curves.easeOut,
-        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
         decoration: BoxDecoration(
           // .segswitch-opt.is-active:surface 底 + shadow-sm;未选透明
           color: active ? c.surface : Colors.transparent,
           borderRadius: BorderRadius.circular(PangolinRadius.full),
           boxShadow: active ? PangolinShadow.sm : null,
         ),
-        child: Row(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: [
-            Icon(o.icon, size: 16, color: active ? c.fg1 : c.fg2),
-            const SizedBox(width: 8),
-            Flexible(
-              child: Text(
+        // FittedBox(scaleDown):放得下则原样(宽段选不变),放不下则图标+文字整体
+        // 等比缩放而非把文字 ellipsis 截断(窄弹层里 Direct/Tunnel/Reject 曾被截成 Dire…)。
+        child: FittedBox(
+          fit: BoxFit.scaleDown,
+          child: Row(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Icon(o.icon, size: 16, color: active ? c.fg1 : c.fg2),
+              const SizedBox(width: 8),
+              Text(
                 o.label,
                 maxLines: 1,
-                overflow: TextOverflow.ellipsis,
                 style: PangolinText.sm.copyWith(
                   color: active ? c.fg1 : c.fg2,
                   fontWeight: FontWeight.w600,
                 ),
               ),
-            ),
-          ],
+            ],
+          ),
         ),
       ),
     );