feat: enable SSE streaming support in Anthropic handler

- Updated AnthropicHandler to check for streaming configuration before handling SSE transform.
- Modified handleStreaming to use the original request body instead of forcing stream to true.
- Adjusted the transformation logic in AnthropicToBifrost to respect the original stream setting.
- Added logging for SSE streaming configuration in the main application.

config/config.go

@@ -16,6 +16,7 @@ type Config struct {
 	LogLevel              string // "debug", "info", or "warn" — console log verbosity
 	RequestTimeoutSeconds int
 	OpenAIModel           string // default model when client omits it
+	Streaming             bool   // enable/disable SSE streaming responses
 }
 
 // Load reads environment variables and returns a populated Config.
@@ -51,6 +52,13 @@ func Load() *Config {
 	openAIApiKey := os.Getenv("OPENAI_KEY")
 	openAIModel := os.Getenv("OPENAI_MODEL")
 
+	streaming := true
+	if v := os.Getenv("STREAMING"); v != "" {
+		if parsed, err := strconv.ParseBool(v); err == nil {
+			streaming = parsed
+		}
+	}
+
 	return &Config{
 		Port:                  port,
 		OpenAIBackend:         openAIBackend,
@@ -61,5 +69,6 @@ func Load() *Config {
 		LogLevel:              logLevel,
 		RequestTimeoutSeconds: timeoutSec,
 		OpenAIModel:           openAIModel,
+		Streaming:             streaming,
 	}
 }