修复：求婚按钮异性判断 - 统一 sex 字段格式

根因：sex 字段数据库存整数(0/1/2)，但前后端判断混用了
字符串('男'/'女')导致比较永远错误。

修复三处：
1. UserController::show() - sex 返回统一转字符串(1→'男' 2→'女' 其他→'')
2. frame.blade.php - chatContext.userSex 注入时同样转字符串
3. MarriageService::propose() - 后端性别校验改用整数(1/2)比较

逻辑链路：
- 未设置性别(sex=0) → '' → x-show && userInfo.sex 为'' falsy → 按钮隐藏 ✓
- 同性(如两个男) → '男'==='男' → !== 为false → 按钮隐藏 ✓
- 异性(男+女) → '男'!=='女' → 按钮显示 ✓

app/Http/Controllers/UserController.php

@@ -44,7 +44,9 @@ class UserController extends Controller
         $activePosition = $targetUser->activePosition?->load('position.department')->position;
         $data = [
             'username' => $targetUser->username,
-            'sex' => $targetUser->sex,
+            'sex' => match ((int) $targetUser->sex) {
+                1 => '男', 2 => '女', default => ''
+            },
             'headface' => $targetUser->headface,
             'usersf' => $targetUser->usersf,
             'user_level' => $targetUser->user_level,

app/Services/MarriageService.php

@@ -47,12 +47,12 @@ class MarriageService
             return ['ok' => false, 'message' => '不能向自己求婚！', 'marriage_id' => null];
         }
 
-        // 只允许异性之间求婚
-        $validSexes = ['男', '女'];
+        // 只允许异性之间求婚（sex 字段：1=男 2=女 0=未设置）
+        $validSexes = [1, 2];
         if (
-            ! in_array($proposer->sex, $validSexes, true) ||
-            ! in_array($target->sex, $validSexes, true) ||
-            $proposer->sex === $target->sex
+            ! in_array((int) $proposer->sex, $validSexes, true) ||
+            ! in_array((int) $target->sex, $validSexes, true) ||
+            (int) $proposer->sex === (int) $target->sex
         ) {
             return ['ok' => false, 'message' => '只有男女双方才能互相求婚，请确认双方性别设置。', 'marriage_id' => null];
         }

resources/views/chat/frame.blade.php

@@ -31,7 +31,7 @@
             roomId: {{ $room->id }},
             userId: {{ $user->id }},
             username: "{{ $user->username }}",
-            userSex: "{{ $user->sex }}",
+            userSex: "{{ match ((int) $user->sex) {1 => '男',2 => '女',default => ''} }}",
             userLevel: {{ $user->user_level }},
             superLevel: {{ $superLevel }},
             levelKick: {{ $levelKick }},