refactor: 解决无法正确加载 .env 的问题

backend/internal/config/config.go

@@ -3,6 +3,8 @@ package config
 import (
 	"fmt"
 	"os"
+	"path/filepath"
+	"runtime"
 	"time"
 
 	"github.com/gin-contrib/cors"
@@ -48,13 +50,30 @@ type Config struct {
 }
 
 func Load() (*Config, error) {
-	var err error
-	err = godotenv.Load("../configs/.env")
-	err = godotenv.Load("./configs/.env")
-	if err != nil {
-		return nil, fmt.Errorf("error loading .env file: %w", err)
+	// 查找go.mod所在的模块根目录
+	_, filename, _, ok := runtime.Caller(0)
+	if !ok {
+		return nil, fmt.Errorf("unable to get caller info")
 	}
 
+	dir := filepath.Dir(filename)
+	for {
+		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil {
+			// 找到模块根目录，加载configs/.env
+			envPath := filepath.Join(dir, "configs", ".env")
+			if err = godotenv.Load(envPath); err == nil {
+				break
+			}
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			break
+		}
+		dir = parent
+	}
+
+	// 如果找不到.env，继续使用环境变量
+
 	cfg := &Config{
 		Server: ServerConfig{
 			Port: getEnv("PORT", "3001"),

backend/internal/config/config_test.go

@@ -0,0 +1,23 @@
+package config
+
+import (
+	"testing"
+)
+
+func TestLoad(t *testing.T) {
+	cfg, err := Load()
+	if err != nil {
+		t.Fatalf("Load() failed: %v", err)
+	}
+
+	if cfg.Server.Port == "" {
+		t.Error("Expected Server.Port to have default value")
+	}
+
+	if cfg.LLM.Provider == "" && cfg.LLM.APIKey == "" {
+		t.Logf("Config loaded - some optional values may be empty (expected if .env not found)")
+	} else {
+		t.Logf("Config loaded successfully. Provider: %s, Model: %s",
+			cfg.LLM.Provider, cfg.LLM.Model)
+	}
+}