refactor(heicode-self): 返回 raw quota + quota_per_unit（与网页台同源换算）

按 HM owner 要求：客户端换算余额应与网页台完全一致。网页台用
raw_quota / quota_per_unit（web renderQuotaCompat，quotaPerUnit 默认 500000、
系统设置可配）。原 /api/heicode/self 预先除好（quotaToDisplayUnit）反而与网页台
不一致、并迫使客户端 ×500000 回推。

改为返回原始 quota/used_quota + quota_per_unit + quota_display_type，
客户端直接 quota / quota_per_unit 即可，和网页台同一公式，去掉所有缩放 hack。

移除不再使用的 quotaToDisplayUnit。go build/vet 通过。

影响面：仅 Manager(HM)，服务桌面客户端余额展示（响应字段语义调整：quota 由
展示值改为原始值，新增 quota_per_unit）。需客户端同步按 quota/quota_per_unit 换算。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

heicode/controller/heicode_self.go

@@ -11,25 +11,10 @@ import (
 	"github.com/heicode/manager/setting/operation_setting"
 )
 
-// quotaToDisplayUnit converts a raw quota integer (DB unit) to the
-// site-configured display unit (USD / CNY / tokens). Mirrors the
-// conversion in billing.go so the desktop "balance pill" shows the
-// same number the user sees in the web dashboard.
-func quotaToDisplayUnit(raw int) float64 {
-	amount := float64(raw)
-	switch operation_setting.GetQuotaDisplayType() {
-	case operation_setting.QuotaDisplayTypeCNY:
-		return amount / common.QuotaPerUnit * operation_setting.USDExchangeRate
-	case operation_setting.QuotaDisplayTypeTokens:
-		return amount
-	default:
-		return amount / common.QuotaPerUnit
-	}
-}
-
-// quotaDisplayUnitLabel names the unit quotaToDisplayUnit produced, so the
-// desktop client can label the balance directly and must NOT divide the
-// already-converted quota again.
+// quotaDisplayUnitLabel names the unit the raw quota is denominated in, so the
+// desktop client converts exactly like the web dashboard:
+//   usd = quota / quota_per_unit   (mirrors web renderQuotaCompat)
+// Returns USD / CNY / tokens.
 func quotaDisplayUnitLabel() string {
 	switch operation_setting.GetQuotaDisplayType() {
 	case operation_setting.QuotaDisplayTypeCNY:
@@ -82,8 +67,9 @@ func GetHeicodeSelf(c *gin.Context) {
 			"display_name":  user.DisplayName,
 			"group":         user.Group,
 			"role":          user.Role,
-			"quota":              quotaToDisplayUnit(user.Quota),
-			"used_quota":         quotaToDisplayUnit(user.UsedQuota),
+			"quota":              user.Quota,
+			"used_quota":         user.UsedQuota,
+			"quota_per_unit":     common.QuotaPerUnit,
 			"quota_display_type": quotaDisplayUnitLabel(),
 			"request_count":      user.RequestCount,
 		},