fix(phase-3): enable circuit breaker for streaming requests

internal/providers/circuit_breaker.go

@@ -50,9 +50,13 @@ func (cbp *CircuitBreakerProvider) ChatCompletion(ctx context.Context, req *mode
 }
 
 func (cbp *CircuitBreakerProvider) ChatCompletionStream(ctx context.Context, req *models.UnifiedRequest) (<-chan *models.ChatCompletionStreamResponse, error) {
-	// Circuit breaker for streaming is tricky. We'll just call the provider directly.
-	// Future: Implement a way to track stream failures in the circuit breaker.
-	return cbp.provider.ChatCompletionStream(ctx, req)
+	result, err := cbp.cb.Execute(func() (interface{}, error) {
+		return cbp.provider.ChatCompletionStream(ctx, req)
+	})
+	if err != nil {
+		return nil, err
+	}
+	return result.(<-chan *models.ChatCompletionStreamResponse), nil
 }
 
 func (cbp *CircuitBreakerProvider) ImageGeneration(ctx context.Context, req *models.ImageGenerationRequest) (*models.ImageGenerationResponse, error) {
@@ -76,6 +80,11 @@ func (cbp *CircuitBreakerProvider) Responses(ctx context.Context, req *models.Re
 }
 
 func (cbp *CircuitBreakerProvider) ResponsesStream(ctx context.Context, req *models.ResponsesRequest) (<-chan *models.ResponsesStreamChunk, error) {
-	// Circuit breaker passthrough for streaming (same pattern as ChatCompletionStream)
-	return cbp.provider.ResponsesStream(ctx, req)
+	result, err := cbp.cb.Execute(func() (interface{}, error) {
+		return cbp.provider.ResponsesStream(ctx, req)
+	})
+	if err != nil {
+		return nil, err
+	}
+	return result.(<-chan *models.ResponsesStreamChunk), nil
 }