fix: move channel close to defer statement in OpenAI streaming methods

## CHANGES

- Move close(channel) to defer statement
- Ensure channel closes even on errors
- Apply fix to sendStreamChatCompletions method
- Apply fix to sendStreamResponses method
- Improve error handling reliability
- Prevent potential channel leaks

plugins/ai/openai/chat_completions.go

@@ -32,6 +32,8 @@ func (o *Client) sendChatCompletions(ctx context.Context, msgs []*chat.ChatCompl
 func (o *Client) sendStreamChatCompletions(
 	msgs []*chat.ChatCompletionMessage, opts *common.ChatOptions, channel chan string,
 ) (err error) {
+	defer close(channel)
+
 	req := o.buildChatCompletionParams(msgs, opts)
 	stream := o.ApiClient.Chat.Completions.NewStreaming(context.Background(), req)
 	for stream.Next() {
@@ -43,7 +45,6 @@ func (o *Client) sendStreamChatCompletions(
 	if stream.Err() == nil {
 		channel <- "\n"
 	}
-	close(channel)
 	return stream.Err()
 }
 

plugins/ai/openai/openai.go

@@ -99,6 +99,8 @@ func (o *Client) SendStream(
 func (o *Client) sendStreamResponses(
 	msgs []*chat.ChatCompletionMessage, opts *common.ChatOptions, channel chan string,
 ) (err error) {
+	defer close(channel)
+
 	req := o.buildResponseParams(msgs, opts)
 	stream := o.ApiClient.Responses.NewStreaming(context.Background(), req)
 	for stream.Next() {
@@ -113,7 +115,6 @@ func (o *Client) sendStreamResponses(
 	if stream.Err() == nil {
 		channel <- "\n"
 	}
-	close(channel)
 	return stream.Err()
 }