Improve config lookup and OpenAI streaming decode

internal/config/config.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"gopkg.in/yaml.v3"
@@ -63,8 +64,19 @@ func Load(path string) (*Config, error) {
 			return nil, err
 		}
 	} else {
-		if err := loadFile("config.yaml", &cfg); err != nil && !errors.Is(err, os.ErrNotExist) {
-			return nil, err
+		candidates := []string{"config.yaml"}
+		if home, err := os.UserHomeDir(); err == nil && strings.TrimSpace(home) != "" {
+			candidates = append(candidates, filepath.Join(home, ".config", "goaichat", "config.yaml"))
+		}
+
+		for _, candidate := range candidates {
+			if err := loadFile(candidate, &cfg); err != nil {
+				if errors.Is(err, os.ErrNotExist) {
+					continue
+				}
+				return nil, err
+			}
+			break
 		}
 	}