feat: add ax serve command with JSON API backed by NodeService

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

service/config_file.go

@@ -11,8 +11,9 @@ import (
 
 type fileConfig struct {
 	path        string
-	User        string   `json:"user"`
-	UserAliases []*Alias `json:"aliases"`
+	User        string       `json:"user"`
+	UserAliases []*Alias     `json:"aliases"`
+	Serve       ServerConfig `json:"serve"`
 }
 
 var defaultAliases = []*Alias{
@@ -140,6 +141,18 @@ func (c *fileConfig) ListAliases() ([]*Alias, error) {
 	return result, nil
 }
 
+func (c *fileConfig) GetServerConfig() ServerConfig {
+	host := c.Serve.Host
+	if host == "" {
+		host = "localhost"
+	}
+	port := c.Serve.Port
+	if port == 0 {
+		port = 7000
+	}
+	return ServerConfig{Host: host, Port: port}
+}
+
 func (c *fileConfig) Save() error {
 	if err := os.MkdirAll(filepath.Dir(c.path), 0755); err != nil {
 		return err