fix(mobile/share): fix referral code overflow, remove team stats & team reward section

- Fix RIGHT OVERFLOWED BY 17 PIXELS: use Flexible on code Text,
  reduce letterSpacing 4→2, reduce horizontal padding
- Remove stats card (direct/team count) from page layout
- Remove 团队层级收益 reward item from reward plan card

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/genex-mobile/lib/features/profile/presentation/pages/share_page.dart

@@ -233,8 +233,6 @@ class _SharePageState extends State<SharePage> {
         children: [
           _buildHeroCard(),           // QR 码（APK 链接）+ 推荐码
           const SizedBox(height: 16),
-          _buildStatsCard(),          // 邀请进度
-          const SizedBox(height: 16),
           _buildRewardPlanCard(),     // 推荐奖励计划（营销区块）
           const SizedBox(height: 16),
           if (_info?.usedCode != null) ...[
@@ -364,7 +362,7 @@ class _SharePageState extends State<SharePage> {
             GestureDetector(
               onTap: _copyCode,
               child: Container(
-                padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
+                padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
                 decoration: BoxDecoration(
                   color: Colors.white.withOpacity(0.15),
                   borderRadius: BorderRadius.circular(40),
@@ -373,18 +371,21 @@ class _SharePageState extends State<SharePage> {
                 child: Row(
                   mainAxisSize: MainAxisSize.min,
                   children: [
-                    Text(
+                    Flexible(
+                      child: Text(
                         _info?.referralCode ?? '------',
                         style: AppTypography.h2.copyWith(
                           color: Colors.white,
-                        letterSpacing: 4,
+                          letterSpacing: 2,
                           fontWeight: FontWeight.w700,
                           fontFamily: 'monospace',
                         ),
+                        overflow: TextOverflow.ellipsis,
                       ),
-                    const SizedBox(width: 12),
+                    ),
+                    const SizedBox(width: 10),
                     Container(
-                      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
+                      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                       decoration: BoxDecoration(
                         color: Colors.white.withOpacity(0.2),
                         borderRadius: BorderRadius.circular(20),
@@ -512,14 +513,6 @@ class _SharePageState extends State<SharePage> {
                 desc: context.t('share.rewardDirectDesc'),
               ),
               const Divider(indent: 60, height: 1),
-              _buildRewardItem(
-                icon: Icons.account_tree_rounded,
-                iconBg: AppColors.infoLight,
-                iconColor: AppColors.info,
-                title: context.t('share.rewardTeam'),
-                desc: context.t('share.rewardTeamDesc'),
-              ),
-              const Divider(indent: 60, height: 1),
               _buildRewardItem(
                 icon: Icons.card_giftcard_rounded,
                 iconBg: AppColors.successLight,