Add api package

Change-Id: Ifcdd1f45c01e98b91c1edef3371332cb4a098e82
diff --git a/server/config/config.go b/server/config/config.go
index baceb04..1a39c6f 100644
--- a/server/config/config.go
+++ b/server/config/config.go
@@ -10,6 +10,7 @@
 
 // Config represents the Staff MVP configuration
 type Config struct {
+	Server ServerConfig  `yaml:"server"`
 	OpenAI OpenAIConfig  `yaml:"openai"`
 	GitHub GitHubConfig  `yaml:"github"`
 	Gerrit GerritConfig  `yaml:"gerrit"`
@@ -18,6 +19,10 @@
 	Git    GitConfig     `yaml:"git"`
 }
 
+type ServerConfig struct {
+	ListenAddress string `yaml:"listen_address"`
+}
+
 // OpenAIConfig represents OpenAI provider configuration
 type OpenAIConfig struct {
 	APIKey     string        `yaml:"api_key"`
@@ -126,6 +131,10 @@
 		config.Gerrit.Project = gerritProject
 	}
 
+	if listenAddr := os.Getenv("LISTEN_ADDRESS"); listenAddr != "" {
+		config.Server.ListenAddress = listenAddr
+	}
+
 	// Re-validate after env overrides
 	if err := validateConfig(*config); err != nil {
 		return nil, fmt.Errorf("invalid configuration after env overrides: %w", err)