Feature/websearch OpenAI (#118)

* feature: add web search for codex models

* fix: use more elegant way to solve the issue.

pkg/migrate/config.go

@@ -108,7 +108,10 @@ func ConvertConfig(data map[string]interface{}) (*config.Config, []string, error
 			case "anthropic":
 				cfg.Providers.Anthropic = pc
 			case "openai":
-				cfg.Providers.OpenAI = pc
+				cfg.Providers.OpenAI = config.OpenAIProviderConfig{
+					ProviderConfig: pc,
+					WebSearch:      getBoolOrDefault(pMap, "web_search", true),
+				}
 			case "openrouter":
 				cfg.Providers.OpenRouter = pc
 			case "groq":
@@ -363,6 +366,13 @@ func getBool(data map[string]interface{}, key string) (bool, bool) {
 	return b, ok
 }
 
+func getBoolOrDefault(data map[string]interface{}, key string, defaultVal bool) bool {
+	if v, ok := getBool(data, key); ok {
+		return v
+	}
+	return defaultVal
+}
+
 func getStringSlice(data map[string]interface{}, key string) []string {
 	v, ok := data[key]
 	if !ok {