feat(payment): 虎皮椒聚合支付 - 官方插件与跨平台可执行文件

新增 xunhupay 官方包，支付 RPC 与宿主只保留订单和验签边界；官方支付包同时带上各系统 provider，避免把 Linux ELF 当成本机入口。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/database/migrations.go

@@ -11,7 +11,7 @@ import (
 	"gorm.io/gorm"
 )
 
-const CurrentSchemaVersion int64 = 18
+const CurrentSchemaVersion int64 = 19
 
 const baselineSchemaChecksum = "sha256:open-ai-canvas-schema-v1-20260830"
 const schemaMigrationAppliedAtIndexChecksum = "sha256:schema-migrations-applied-at-index-v2-20260830"
@@ -76,6 +76,7 @@ var schemaMigrations = []migration{
 	{version: 18, name: "agent_memory_settings", checksum: "sha256:agent-memory-settings-v18-20260917", apply: func(tx *gorm.DB) error {
 		return tx.AutoMigrate(&model.AgentMemorySetting{})
 	}},
+	{version: 19, name: "payment_plugin_version", checksum: "sha256:payment-plugin-version-v19-20260917", apply: migrateSchemaV19},
 }
 
 func migrateSchemaV14(tx *gorm.DB) error {
@@ -239,6 +240,28 @@ func migrateSchemaV5(tx *gorm.DB) error {
 	return nil
 }
 
+func migrateSchemaV19(tx *gorm.DB) error {
+	for _, value := range []any{&model.PaymentProviderConfig{}, &model.PaymentOrder{}} {
+		if !tx.Migrator().HasTable(value) {
+			continue
+		}
+		if err := addPaymentPluginVersionColumn(tx, value); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func addPaymentPluginVersionColumn(tx *gorm.DB, value any) error {
+	if tx.Migrator().HasColumn(value, "plugin_version") {
+		return nil
+	}
+	if err := tx.Migrator().AddColumn(value, "PluginVersion"); err != nil {
+		return fmt.Errorf("增加支付插件版本列：%w", err)
+	}
+	return nil
+}
+
 func migrateSchemaV6(tx *gorm.DB) error {
 	if !tx.Migrator().HasTable(&model.Resource{}) {
 		return fmt.Errorf("资源表不存在")