feat: scaffold go backend foundation

internal/config/config.go

@@ -0,0 +1,37 @@
+package config
+
+import "os"
+
+const (
+	defaultHTTPAddr        = ":8080"
+	defaultEnvironment     = "development"
+	defaultModelKey        = "deepseek-v4-flash"
+	defaultThirdOneBin     = "thirdone"
+	defaultWorkflowRuntime = ""
+)
+
+type Config struct {
+	HTTPAddr        string
+	Environment     string
+	WorkflowRuntime string
+	ModelKey        string
+	ThirdOneBin     string
+}
+
+func LoadFromEnv() Config {
+	return Config{
+		HTTPAddr:        envOrDefault("TUTOR_HTTP_ADDR", defaultHTTPAddr),
+		Environment:     envOrDefault("TUTOR_ENV", defaultEnvironment),
+		WorkflowRuntime: envOrDefault("TUTOR_WORKFLOW_RUNTIME", defaultWorkflowRuntime),
+		ModelKey:        envOrDefault("TUTOR_MODEL_KEY", defaultModelKey),
+		ThirdOneBin:     envOrDefault("THIRDONE_BIN", defaultThirdOneBin),
+	}
+}
+
+func envOrDefault(key string, fallback string) string {
+	value := os.Getenv(key)
+	if value == "" {
+		return fallback
+	}
+	return value
+}