feat: configurable tool pricing, Sub2API channel, and alpha search billing

Add admin-configurable tool-call prices with cross-provider surcharge
settlement, Sub2API channel support, /v1/alpha/search relay, and usage-log
surcharge UI.

controller/option.go

@@ -235,6 +235,15 @@ func UpdateOption(c *gin.Context) {
 			})
 			return
 		}
+	case operation_setting.ToolPriceOptionKey:
+		err = operation_setting.ValidateToolPricesJSON(option.Value.(string))
+		if err != nil {
+			c.JSON(http.StatusOK, gin.H{
+				"success": false,
+				"message": err.Error(),
+			})
+			return
+		}
 	case "ImageRatio":
 		err = ratio_setting.UpdateImageRatioByJSONString(option.Value.(string))
 		if err != nil {

controller/relay.go

@@ -49,6 +49,8 @@ func relayHandler(c *gin.Context, info *relaycommon.RelayInfo) *types.NewAPIErro
 		err = relay.EmbeddingHelper(c, info)
 	case relayconstant.RelayModeResponses, relayconstant.RelayModeResponsesCompact:
 		err = relay.ResponsesHelper(c, info)
+	case relayconstant.RelayModeAlphaSearch:
+		err = relay.AlphaSearchHelper(c, info)
 	default:
 		err = relay.TextHelper(c, info)
 	}