feat(admin): 更新后台权限管理与同步逻辑，简化权限检查并优化文档

- 新增后台 RBAC 相关文档，提供权限目录与维护命令说明。
- 移除不必要的角色资源同步检查，简化权限审计命令。
- 更新权限描述与同步逻辑，确保一致性与可维护性。
- 统一权限注册表，替换过时的权限别名，增强代码可读性。

app/Http/Controllers/Api/V1/Setting/SettingIndexController.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Http\Controllers\Api\V1\Setting;
+
+use App\Http\Controllers\Controller;
+use App\Models\LotterySetting;
+use App\Support\ApiResponse;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+/**
+ * 玩家端/公开：读取 KV 配置（公开访问）
+ */
+final class SettingIndexController extends Controller
+{
+    public function __invoke(Request $request): JsonResponse
+    {
+        $group = $request->query('group');
+        
+        $query = LotterySetting::query()->orderBy('setting_key');
+
+        if (! empty($group)) {
+            $query->where('group_name', $group);
+        }
+
+        $items = $query->get()->map(fn (LotterySetting $s): array => [
+            'key' => $s->setting_key,
+            'value' => $s->value_json,
+            'group' => $s->group_name,
+            'description' => $s->description_zh,
+        ]);
+
+        return ApiResponse::success(['items' => $items]);
+    }
+}