fix: make chain and limiter updates idempotent

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

go-gost/x/socket/chain.go

@@ -43,8 +43,8 @@ func updateChain(req updateChainRequest) error {
 
 	name := strings.TrimSpace(req.Chain)
 
-	if !registry.ChainRegistry().IsRegistered(name) {
-		return errors.New("chain " + name + " not found")
+	if registry.ChainRegistry().IsRegistered(name) {
+		registry.ChainRegistry().Unregister(name)
 	}
 
 	req.Data.Name = name
@@ -54,19 +54,22 @@ func updateChain(req updateChainRequest) error {
 		return errors.New("create chain " + name + " failed: " + err.Error())
 	}
 
-	registry.ChainRegistry().Unregister(name)
-
 	if err := registry.ChainRegistry().Register(name, v); err != nil {
 		return errors.New("chain " + name + " already exists")
 	}
 
 	config.OnUpdate(func(c *config.Config) error {
+		found := false
 		for i := range c.Chains {
 			if c.Chains[i].Name == name {
 				c.Chains[i] = &req.Data
+				found = true
 				break
 			}
 		}
+		if !found {
+			c.Chains = append(c.Chains, &req.Data)
+		}
 		return nil
 	})
 
@@ -77,10 +80,9 @@ func deleteChain(req deleteChainRequest) error {
 
 	name := strings.TrimSpace(req.Chain)
 
-	if !registry.ChainRegistry().IsRegistered(name) {
-		return errors.New("chain " + name + " not found")
+	if registry.ChainRegistry().IsRegistered(name) {
+		registry.ChainRegistry().Unregister(name)
 	}
-	registry.ChainRegistry().Unregister(name)
 
 	config.OnUpdate(func(c *config.Config) error {
 		chains := c.Chains

go-gost/x/socket/limiter.go

@@ -37,27 +37,30 @@ func updateLimiter(req updateLimiterRequest) error {
 
 	name := strings.TrimSpace(req.Limiter)
 
-	if !registry.TrafficLimiterRegistry().IsRegistered(name) {
-		return errors.New("limiter " + name + " not found")
+	if registry.TrafficLimiterRegistry().IsRegistered(name) {
+		registry.TrafficLimiterRegistry().Unregister(name)
 	}
 
 	req.Data.Name = name
 
 	v := parser.ParseTrafficLimiter(&req.Data)
 
-	registry.TrafficLimiterRegistry().Unregister(name)
-
 	if err := registry.TrafficLimiterRegistry().Register(name, v); err != nil {
 		return errors.New("limiter " + name + " already exists")
 	}
 
 	config.OnUpdate(func(c *config.Config) error {
+		found := false
 		for i := range c.Limiters {
 			if c.Limiters[i].Name == name {
 				c.Limiters[i] = &req.Data
+				found = true
 				break
 			}
 		}
+		if !found {
+			c.Limiters = append(c.Limiters, &req.Data)
+		}
 		return nil
 	})
 
@@ -68,10 +71,9 @@ func deleteLimiter(req deleteLimiterRequest) error {
 
 	name := strings.TrimSpace(req.Limiter)
 
-	if !registry.TrafficLimiterRegistry().IsRegistered(name) {
-		return errors.New("limiter " + name + " not found")
+	if registry.TrafficLimiterRegistry().IsRegistered(name) {
+		registry.TrafficLimiterRegistry().Unregister(name)
 	}
-	registry.TrafficLimiterRegistry().Unregister(name)
 
 	config.OnUpdate(func(c *config.Config) error {
 		limiteres := c.Limiters