feat: Add self-use mode for model ratio and price configuration

- Introduce `SelfUseModeEnabled` setting to allow flexible model ratio configuration
- Update error handling to provide more informative messages when model ratios are not set
- Modify pricing and relay logic to support self-use mode
- Add UI toggle for enabling self-use mode in operation settings
- Implement fallback mechanism for model ratios when self-use mode is enabled

controller/pricing.go

@@ -2,7 +2,6 @@ package controller
 
 import (
 	"github.com/gin-gonic/gin"
-	"one-api/common"
 	"one-api/model"
 	"one-api/setting"
 )
@@ -40,7 +39,7 @@ func GetPricing(c *gin.Context) {
 }
 
 func ResetModelRatio(c *gin.Context) {
-	defaultStr := common.DefaultModelRatio2JSONString()
+	defaultStr := setting.DefaultModelRatio2JSONString()
 	err := model.UpdateOption("ModelRatio", defaultStr)
 	if err != nil {
 		c.JSON(200, gin.H{
@@ -49,7 +48,7 @@ func ResetModelRatio(c *gin.Context) {
 		})
 		return
 	}
-	err = common.UpdateModelRatioByJSONString(defaultStr)
+	err = setting.UpdateModelRatioByJSONString(defaultStr)
 	if err != nil {
 		c.JSON(200, gin.H{
 			"success": false,