fix(mining-app): update profile page - hide items and rename label

- Rename "团队层级" to "团队下级" in stats row
- Hide "实名认证" option from account settings
- Hide "我的邀请码" card section entirely
- Remove unused _buildInvitationCard and _buildActionButton methods

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/pages/profile/profile_page.dart

@@ -23,7 +23,6 @@ class ProfilePage extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final user = ref.watch(userNotifierProvider);
     final statsAsync = ref.watch(userStatsProvider);
-    final invitationCode = ref.watch(invitationCodeProvider);
 
     final isStatsLoading = statsAsync.isLoading;
     final stats = statsAsync.valueOrNull;
@@ -51,11 +50,6 @@ class ProfilePage extends ConsumerWidget {
 
                 const SizedBox(height: 16),
 
-                // 邀请码卡片
-                _buildInvitationCard(context, invitationCode),
-
-                const SizedBox(height: 16),
-
                 // 账户设置
                 _buildAccountSettings(context, user),
 
@@ -264,7 +258,7 @@ class ProfilePage extends ConsumerWidget {
           ),
           _buildDivider(),
           _buildStatItem(
-            '团队层级',
+            '团队下级',
             stats?.unlockedLevelDepth.toString() ?? '0',
             isLoading,
           ),
@@ -312,108 +306,6 @@ class ProfilePage extends ConsumerWidget {
     );
   }
 
-  Widget _buildInvitationCard(BuildContext context, String invitationCode) {
-    return Container(
-      margin: const EdgeInsets.symmetric(horizontal: 16),
-      padding: const EdgeInsets.all(16),
-      decoration: BoxDecoration(
-        color: Colors.white,
-        borderRadius: BorderRadius.circular(12),
-      ),
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          const Text(
-            '我的邀请码',
-            style: TextStyle(
-              fontSize: 14,
-              color: _grayText,
-            ),
-          ),
-          const SizedBox(height: 12),
-          Row(
-            children: [
-              Expanded(
-                child: Container(
-                  padding: const EdgeInsets.symmetric(
-                    horizontal: 16,
-                    vertical: 12,
-                  ),
-                  decoration: BoxDecoration(
-                    color: _bgGray,
-                    borderRadius: BorderRadius.circular(8),
-                  ),
-                  child: Text(
-                    invitationCode,
-                    style: const TextStyle(
-                      fontSize: 18,
-                      fontWeight: FontWeight.bold,
-                      color: _darkText,
-                      letterSpacing: 2,
-                    ),
-                  ),
-                ),
-              ),
-              const SizedBox(width: 12),
-              _buildActionButton(
-                icon: Icons.copy,
-                label: '复制',
-                onTap: () {
-                  Clipboard.setData(ClipboardData(text: invitationCode));
-                  ScaffoldMessenger.of(context).showSnackBar(
-                    const SnackBar(
-                      content: Text('邀请码已复制'),
-                      duration: Duration(seconds: 1),
-                    ),
-                  );
-                },
-              ),
-              const SizedBox(width: 8),
-              _buildActionButton(
-                icon: Icons.share,
-                label: '分享',
-                onTap: () {
-                  // TODO: 分享功能
-                },
-              ),
-            ],
-          ),
-        ],
-      ),
-    );
-  }
-
-  Widget _buildActionButton({
-    required IconData icon,
-    required String label,
-    required VoidCallback onTap,
-  }) {
-    return GestureDetector(
-      onTap: onTap,
-      child: Container(
-        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
-        decoration: BoxDecoration(
-          color: _orange,
-          borderRadius: BorderRadius.circular(8),
-        ),
-        child: Row(
-          children: [
-            Icon(icon, size: 16, color: Colors.white),
-            const SizedBox(width: 4),
-            Text(
-              label,
-              style: const TextStyle(
-                fontSize: 12,
-                color: Colors.white,
-                fontWeight: FontWeight.w500,
-              ),
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-
   Widget _buildAccountSettings(BuildContext context, UserState user) {
     return Container(
       margin: const EdgeInsets.symmetric(horizontal: 16),
@@ -440,18 +332,6 @@ class ProfilePage extends ConsumerWidget {
             label: '账户安全',
             onTap: () => context.push(Routes.changePassword),
           ),
-          _buildSettingItem(
-            icon: Icons.verified_user,
-            label: '实名认证',
-            trailing: Text(
-              user.isKycVerified ? '已认证' : '未认证',
-              style: TextStyle(
-                fontSize: 14,
-                color: user.isKycVerified ? _green : _lightGray,
-              ),
-            ),
-            onTap: () {},
-          ),
           _buildSettingItem(
             icon: Icons.lock_outline,
             label: '支付密码',