fix: round-3 review fixes for RPM limiting

- Add sanitizeExtraBaseRPM to BulkUpdate handler (was missing)
- Add WindowCost scheduling checks to legacy non-sticky selection
  paths (4 sites), matching existing sticky + load-aware coverage
- Export ParseExtraInt from service package, remove duplicate
  parseExtraIntForValidation from admin handler

backend/internal/handler/admin/account_handler.go

@@ -1082,6 +1082,8 @@ func (h *AccountHandler) BulkUpdate(c *gin.Context) {
 		response.BadRequest(c, "rate_multiplier must be >= 0")
 		return
 	}
+	// base_rpm 输入校验：负值归零，超过 10000 截断
+	sanitizeExtraBaseRPM(req.Extra)
 
 	// 确定是否跳过混合渠道检查
 	skipCheck := req.ConfirmMixedChannelRisk != nil && *req.ConfirmMixedChannelRisk
@@ -1751,7 +1753,7 @@ func sanitizeExtraBaseRPM(extra map[string]any) {
 	if !ok {
 		return
 	}
-	v := parseExtraIntForValidation(raw)
+	v := service.ParseExtraInt(raw)
 	if v < 0 {
 		v = 0
 	} else if v > 10000 {
@@ -1760,24 +1762,3 @@ func sanitizeExtraBaseRPM(extra map[string]any) {
 	extra["base_rpm"] = v
 }
 
-// parseExtraIntForValidation 从 extra 字段的 any 值解析为 int，用于输入校验。
-// 支持 int, int64, float64, json.Number, string 类型。
-func parseExtraIntForValidation(value any) int {
-	switch v := value.(type) {
-	case int:
-		return v
-	case int64:
-		return int(v)
-	case float64:
-		return int(v)
-	case json.Number:
-		if i, err := v.Int64(); err == nil {
-			return int(i)
-		}
-	case string:
-		if i, err := strconv.Atoi(strings.TrimSpace(v)); err == nil {
-			return i
-		}
-	}
-	return 0
-}

backend/internal/service/account.go

@@ -1274,6 +1274,12 @@ func parseExtraFloat64(value any) float64 {
 }
 
 // parseExtraInt 从 extra 字段解析 int 值
+// ParseExtraInt 从 extra 字段的 any 值解析为 int。
+// 支持 int, int64, float64, json.Number, string 类型，无法解析时返回 0。
+func ParseExtraInt(value any) int {
+	return parseExtraInt(value)
+}
+
 func parseExtraInt(value any) int {
 	switch v := value.(type) {
 	case int:

backend/internal/service/gateway_service.go

@@ -2641,6 +2641,9 @@ func (s *GatewayService) selectAccountForModelWithPlatform(ctx context.Context,
 			if !s.isAccountSchedulableForModelSelection(ctx, acc, requestedModel) {
 				continue
 			}
+			if !s.isAccountSchedulableForWindowCost(ctx, acc, false) {
+				continue
+			}
 			if !s.isAccountSchedulableForRPM(ctx, acc, false) {
 				continue
 			}
@@ -2737,6 +2740,9 @@ func (s *GatewayService) selectAccountForModelWithPlatform(ctx context.Context,
 		if !s.isAccountSchedulableForModelSelection(ctx, acc, requestedModel) {
 			continue
 		}
+		if !s.isAccountSchedulableForWindowCost(ctx, acc, false) {
+			continue
+		}
 		if !s.isAccountSchedulableForRPM(ctx, acc, false) {
 			continue
 		}
@@ -2865,6 +2871,9 @@ func (s *GatewayService) selectAccountWithMixedScheduling(ctx context.Context, g
 			if !s.isAccountSchedulableForModelSelection(ctx, acc, requestedModel) {
 				continue
 			}
+			if !s.isAccountSchedulableForWindowCost(ctx, acc, false) {
+				continue
+			}
 			if !s.isAccountSchedulableForRPM(ctx, acc, false) {
 				continue
 			}
@@ -2963,6 +2972,9 @@ func (s *GatewayService) selectAccountWithMixedScheduling(ctx context.Context, g
 		if !s.isAccountSchedulableForModelSelection(ctx, acc, requestedModel) {
 			continue
 		}
+		if !s.isAccountSchedulableForWindowCost(ctx, acc, false) {
+			continue
+		}
 		if !s.isAccountSchedulableForRPM(ctx, acc, false) {
 			continue
 		}