Reintroduce friend support for live

- Return approved friends in live/partyList
- Use the selected support center unit during live play
- Fall back to self support when no friend is available
- Align friend_status with client display expectations

Signed-off-by: Sean Du <do4suki@gmail.com>

internal/handler/live/play.go

@@ -312,18 +312,10 @@ func play(ctx *gin.Context) {
 		}
 
 		// 好友主唱技能加成
-		// TODO 好友支援存入数据库
-		// var tomoUnitId int64
-		// partyList := gjson.Parse(utils.ReadAllText("assets/serverdata/partylist.json")).Get("response_data.party_list")
-		// partyList.ForEach(func(key, value gjson.Result) bool {
-		// 	if value.Get("user_info.user_id").Int() == playReq.PartyUserID {
-		// 		tomoUnitId = value.Get("center_unit_info.unit_id").Int()
-		// 		return false
-		// 	}
-		// 	return true
-		// })
-		// TODO: 好友功能实装前先使用自己的卡组助战
-		tomoUnitId := myCenterUnitId
+		tomoUnitId, err := getSupportCenterUnitID(ss, int(playReq.PartyUserID), myCenterUnitId)
+		if ss.CheckErr(err) {
+			return
+		}
 		// fmt.Println("好友UnitID:", tomoUnitId)
 
 		// 好友主唱技能加成：主C技能（这里不使用新C技能，即以某属性的百分比提升另一属性）