Add custom headers to direct connections (#2922)

* Add custom headers to direct connections

* Address custom header review feedback

* Fix direct connection header integration

* Fix desktop relay E2E transport setup

---------

Co-authored-by: Claude <claude@Claudes-Mac-mini.local>
Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

packages/app/src/i18n/resources/ja.ts

@@ -1419,6 +1419,19 @@ export const ja: TranslationResources = {
         show: "詳細設定を表示",
         hide: "詳細設定を非表示",
       },
+      headers: {
+        title: "カスタムヘッダー",
+        add: "ヘッダーを追加",
+        name: "名前",
+        value: "値",
+        remove: "ヘッダーを削除",
+        errors: {
+          missingName: "各ヘッダーの名前を入力してください",
+          invalidName: "{{name}} は有効なヘッダー名ではありません",
+          invalidValue: "{{name}} に無効な改行が含まれています",
+          duplicateName: "{{name}} が複数回入力されています",
+        },
+      },
       passwordVisibility: {
         show: "パスワードを表示",
         hide: "パスワードを非表示",