修复新人等级被降为零

tests/Feature/ChatControllerTest.php

@@ -801,6 +801,39 @@ class ChatControllerTest extends TestCase
         $this->assertGreaterThanOrEqual(0, $user->exp_num); // Might be 1 depending on sysparam
     }
 
+    /**
+     * 测试低经验新人心跳后不会被降到 0 级，刷新后仍可进入默认房间。
+     */
+    public function test_low_exp_newbie_keeps_minimum_level_after_heartbeat(): void
+    {
+        Sysparam::updateOrCreate(['alias' => 'exp_per_heartbeat'], ['body' => '0']);
+        Sysparam::updateOrCreate(['alias' => 'jjb_per_heartbeat'], ['body' => '0']);
+        Sysparam::updateOrCreate(['alias' => 'auto_event_chance'], ['body' => '0']);
+        Cache::flush();
+
+        $room = Room::create([
+            'room_name' => 'newhb',
+            'permit_level' => 1,
+            'door_open' => true,
+        ]);
+        $user = User::factory()->create([
+            'user_level' => 1,
+            'exp_num' => 0,
+            'has_received_new_gift' => true,
+        ]);
+
+        $this->actingAs($user)->get(route('chat.room', $room->id))->assertOk();
+
+        $heartbeatResponse = $this->actingAs($user)->postJson(route('chat.heartbeat', $room->id));
+
+        $heartbeatResponse->assertOk();
+        $heartbeatResponse->assertJsonPath('data.user_level', 1);
+        $this->assertSame(1, $user->fresh()->user_level);
+
+        Redis::del("room:{$room->id}:alive:{$user->username}");
+        $this->actingAs($user)->get(route('chat.room', $room->id))->assertOk();
+    }
+
     /**
      * 测试显式退房会清理 Redis 在线状态。
      */