fix: golangci-lint 零告警通过 (57→0) + gofumpt/goimports 全量格式化

## CI 修复 (P0/P1)

P0 — 编译阻塞:
  - interfaces.go: postUseCase ISP 接口移除不用的 Create/Update/Delete

P1 — 必须修复:
  - ST1000: 为 13 个包添加包注释 (common/config/model/service/...)
  - ST1005: redis_store.go 全部错误消息改为小写开头
  - errcheck (19处): defer Close()→闭包忽略, notifier.Create→_=, r.Run→检查error
  - errorlint (9处): switch-on-error→errors.Is 链, ==→errors.Is
  - ST1020/ST1022: 导出符号注释以符号名开头

P2 — 安全评审:
  - gosec (12处): G203/G301/G304/G306 添加 nolint 注释并附理由

P3 — 清理:
  - unused: 移除 hasUnicode/energyStore/current/energyAdminUseCase
  - gofumpt + goimports 全量格式化 (35+ 文件)

internal/controller/admin/admin_energy_api_controller.go

@@ -1,6 +1,7 @@
 package admin
 
 import (
+	"errors"
 	"net/http"
 	"strconv"
 
@@ -44,7 +45,7 @@ func (ac *AdminEnergyController) AdjustEnergy(c *gin.Context) {
 	}
 
 	if err := ac.energySvc.AdminAdjust(operatorUID.(uint), req.UserIDs, req.Amount, req.Description, req.Mode); err != nil {
-		if err == common.ErrInsufficientFund {
+		if errors.Is(err, common.ErrInsufficientFund) {
 			common.Error(c, http.StatusBadRequest, "公户余额不足，无法执行操作")
 			return
 		}
@@ -99,7 +100,7 @@ func (ac *AdminEnergyController) GetFundBalance(c *gin.Context) {
 		return
 	}
 	common.Ok(c, gin.H{
-		"balance":        balance,
+		"balance":         balance,
 		"balance_display": float64(balance) / 10,
 	})
 }