fix: add context to HTTP request in getToken and simplify HTTP client initialization

storage/alist/token.go

@@ -18,7 +18,7 @@ func (a *Alist) getToken(ctx context.Context) error {
 		return fmt.Errorf("failed to marshal login request: %w", err)
 	}
 
-	req, err := http.NewRequest(http.MethodPost, a.baseURL+"/api/auth/login", bytes.NewBuffer(loginBody))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, a.baseURL+"/api/auth/login", bytes.NewBuffer(loginBody))
 	if err != nil {
 		return fmt.Errorf("failed to create login request: %w", err)
 	}

storage/alist/utils.go

@@ -5,19 +5,11 @@ import (
 	"time"
 )
 
-var (
-	httpClient *http.Client
-)
-
 func getHttpClient() *http.Client {
-	if httpClient != nil {
-		return httpClient
-	}
-	httpClient = &http.Client{
+	return &http.Client{
 		Timeout: 12 * time.Hour,
 		Transport: &http.Transport{
 			TLSHandshakeTimeout: 10 * time.Second,
 		},
 	}
-	return httpClient
 }