docs(i18n): update translations for email, GnuPG, key-server and version modules

* Refresh and add localized strings across multiple modules (email, GnuPG
  info, key-server sync, version checking and key search) to improve UI
  coverage and clarity.
* Restore and standardize email metadata labels and validation messages,
  and expand EML/email-operation error texts to provide clearer guidance
  for end users and troubleshooting.
* Introduce localized UI entries for `GnuPGInfo` and enhance `SearchKeyDialog`
  translations to make key-search and GnuPG information screens usable in
  several locales.
* Harmonize labels (e.g., CC/BCC/From/To/Subject/Date), warnings and file
  I/O messages to improve consistency and readability.
* No functional logic changes; purely translation/localization updates.

5 files changed, 46 insertions, 46 deletions

diff --git a/src/m_ver_check/ts/ModuleVersionChecking.de_DE.ts b/src/m_ver_check/ts/ModuleVersionChecking.de_DE.ts
index 30b66e2..8e728f1 100644
--- a/src/m_ver_check/ts/ModuleVersionChecking.de_DE.ts
+++ b/src/m_ver_check/ts/ModuleVersionChecking.de_DE.ts
@@ -7,32 +7,32 @@
         <location filename="../VersionCheckingModule.cpp" line="109"/>
         <location filename="../VersionCheckingModule.cpp" line="171"/>
         <source>Check for Updates</source>
-        <translation type="unfinished">Nach Updates suchen</translation>
+        <translation>Nach Updates suchen</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="172"/>
         <source>Check for updates from the Internet.</source>
-        <translation type="unfinished"></translation>
+        <translation>Nach Updates im Internet suchen.</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="292"/>
         <source>Checking for version updates when the application starts.</source>
-        <translation type="unfinished"></translation>
+        <translation>Prüft beim Start der Anwendung auf Versionsupdates.</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="304"/>
         <source>GitHub</source>
-        <translation type="unfinished"></translation>
+        <translation>GitHub</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="307"/>
         <source>BKTUS.com</source>
-        <translation type="unfinished"></translation>
+        <translation>BKTUS.com</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="312"/>
         <source>Update Checking API:</source>
-        <translation type="unfinished"></translation>
+        <translation>API für die Update-Prüfung:</translation>
     </message>
 </context>
 <context>
@@ -90,12 +90,12 @@
     <message>
         <location filename="../UpdateTab.cpp" line="124"/>
         <source>to check for the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>um die neueste Version zu überprüfen.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="196"/>
         <source>You are using the latest version. No action is required.</source>
-        <translation type="unfinished"></translation>
+        <translation>Sie verwenden die neueste Version. Es sind keine weiteren Schritte erforderlich.</translation>
     </message>
     <message>
         <source>to check for the latest stable version.</source>
@@ -133,12 +133,12 @@
         <location filename="../UpdateTab.cpp" line="164"/>
         <location filename="../UpdateTab.cpp" line="177"/>
         <source>to download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>um die neueste Version herunterzuladen.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="172"/>
         <source>This version is either withdrawn due to critical issues or is an unreleased build. Please stop using it and download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>Diese Version wurde entweder aufgrund kritischer Probleme zurückgezogen oder ist ein nicht freigegebenes Build. Bitte verwenden Sie sie nicht weiter und laden Sie die neueste Version herunter.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="184"/>
diff --git a/src/m_ver_check/ts/ModuleVersionChecking.fr_FR.ts b/src/m_ver_check/ts/ModuleVersionChecking.fr_FR.ts
index bdd4185..6bb5844 100644
--- a/src/m_ver_check/ts/ModuleVersionChecking.fr_FR.ts
+++ b/src/m_ver_check/ts/ModuleVersionChecking.fr_FR.ts
@@ -7,32 +7,32 @@
         <location filename="../VersionCheckingModule.cpp" line="109"/>
         <location filename="../VersionCheckingModule.cpp" line="171"/>
         <source>Check for Updates</source>
-        <translation type="unfinished">Vérifier les mises à jour</translation>
+        <translation>Vérifier les mises à jour</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="172"/>
         <source>Check for updates from the Internet.</source>
-        <translation type="unfinished"></translation>
+        <translation>Vérifier les mises à jour sur Internet.</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="292"/>
         <source>Checking for version updates when the application starts.</source>
-        <translation type="unfinished"></translation>
+        <translation>Vérification des mises à jour au démarrage de l&apos;application.</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="304"/>
         <source>GitHub</source>
-        <translation type="unfinished"></translation>
+        <translation>GitHub</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="307"/>
         <source>BKTUS.com</source>
-        <translation type="unfinished"></translation>
+        <translation>BKTUS.com</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="312"/>
         <source>Update Checking API:</source>
-        <translation type="unfinished"></translation>
+        <translation>API de vérification des mises à jour :</translation>
     </message>
 </context>
 <context>
@@ -90,12 +90,12 @@
     <message>
         <location filename="../UpdateTab.cpp" line="124"/>
         <source>to check for the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>pour vérifier la dernière version.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="196"/>
         <source>You are using the latest version. No action is required.</source>
-        <translation type="unfinished"></translation>
+        <translation>Vous utilisez la dernière version. Aucune action n&apos;est requise.</translation>
     </message>
     <message>
         <source>to check for the latest stable version.</source>
@@ -133,12 +133,12 @@
         <location filename="../UpdateTab.cpp" line="164"/>
         <location filename="../UpdateTab.cpp" line="177"/>
         <source>to download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>pour télécharger la dernière version.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="172"/>
         <source>This version is either withdrawn due to critical issues or is an unreleased build. Please stop using it and download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>Cette version a été retirée en raison de problèmes critiques ou il s’agit d’une version non publiée. Veuillez cesser de l’utiliser et télécharger la dernière version.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="184"/>
diff --git a/src/m_ver_check/ts/ModuleVersionChecking.it_IT.ts b/src/m_ver_check/ts/ModuleVersionChecking.it_IT.ts
index 6e405d6..561d5cb 100644
--- a/src/m_ver_check/ts/ModuleVersionChecking.it_IT.ts
+++ b/src/m_ver_check/ts/ModuleVersionChecking.it_IT.ts
@@ -7,32 +7,32 @@
         <location filename="../VersionCheckingModule.cpp" line="109"/>
         <location filename="../VersionCheckingModule.cpp" line="171"/>
         <source>Check for Updates</source>
-        <translation type="unfinished">Verifica aggiornamenti</translation>
+        <translation>Verifica aggiornamenti</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="172"/>
         <source>Check for updates from the Internet.</source>
-        <translation type="unfinished"></translation>
+        <translation>Verifica la presenza di aggiornamenti tramite Internet.</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="292"/>
         <source>Checking for version updates when the application starts.</source>
-        <translation type="unfinished"></translation>
+        <translation>Verifica aggiornamenti di versione all&apos;avvio dell&apos;applicazione.</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="304"/>
         <source>GitHub</source>
-        <translation type="unfinished"></translation>
+        <translation>GitHub</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="307"/>
         <source>BKTUS.com</source>
-        <translation type="unfinished"></translation>
+        <translation>BKTUS.com</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="312"/>
         <source>Update Checking API:</source>
-        <translation type="unfinished"></translation>
+        <translation>API di verifica aggiornamenti:</translation>
     </message>
 </context>
 <context>
@@ -90,12 +90,12 @@
     <message>
         <location filename="../UpdateTab.cpp" line="124"/>
         <source>to check for the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>per controllare l&apos;ultima versione.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="196"/>
         <source>You are using the latest version. No action is required.</source>
-        <translation type="unfinished"></translation>
+        <translation>Stai utilizzando l&apos;ultima versione. Non è necessaria alcuna azione.</translation>
     </message>
     <message>
         <source>to check for the latest stable version.</source>
@@ -133,12 +133,12 @@
         <location filename="../UpdateTab.cpp" line="164"/>
         <location filename="../UpdateTab.cpp" line="177"/>
         <source>to download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>per scaricare l&apos;ultima versione.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="172"/>
         <source>This version is either withdrawn due to critical issues or is an unreleased build. Please stop using it and download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>Questa versione è stata ritirata per problemi critici oppure è una build non rilasciata. Smetti di usarla e scarica l&apos;ultima versione.</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="184"/>
diff --git a/src/m_ver_check/ts/ModuleVersionChecking.zh_CN.ts b/src/m_ver_check/ts/ModuleVersionChecking.zh_CN.ts
index 0387de9..3893bca 100644
--- a/src/m_ver_check/ts/ModuleVersionChecking.zh_CN.ts
+++ b/src/m_ver_check/ts/ModuleVersionChecking.zh_CN.ts
@@ -22,12 +22,12 @@
     <message>
         <location filename="../VersionCheckingModule.cpp" line="304"/>
         <source>GitHub</source>
-        <translation></translation>
+        <translation>GitHub</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="307"/>
         <source>BKTUS.com</source>
-        <translation></translation>
+        <translation>BKTUS.com</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="312"/>
@@ -90,12 +90,12 @@
     <message>
         <location filename="../UpdateTab.cpp" line="124"/>
         <source>to check for the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>检查最新版本</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="196"/>
         <source>You are using the latest version. No action is required.</source>
-        <translation type="unfinished"></translation>
+        <translation>您正在使用最新版本。无需执行任何操作。</translation>
     </message>
     <message>
         <source>to check for the latest stable version.</source>
@@ -133,12 +133,12 @@
         <location filename="../UpdateTab.cpp" line="164"/>
         <location filename="../UpdateTab.cpp" line="177"/>
         <source>to download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>下载最新版本</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="172"/>
         <source>This version is either withdrawn due to critical issues or is an unreleased build. Please stop using it and download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>此版本可能因严重问题而被撤回，或为未发布版本。请停止使用并下载最新版本。</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="184"/>
diff --git a/src/m_ver_check/ts/ModuleVersionChecking.zh_TW.ts b/src/m_ver_check/ts/ModuleVersionChecking.zh_TW.ts
index 3bcdd90..4fb6db3 100644
--- a/src/m_ver_check/ts/ModuleVersionChecking.zh_TW.ts
+++ b/src/m_ver_check/ts/ModuleVersionChecking.zh_TW.ts
@@ -7,32 +7,32 @@
         <location filename="../VersionCheckingModule.cpp" line="109"/>
         <location filename="../VersionCheckingModule.cpp" line="171"/>
         <source>Check for Updates</source>
-        <translation type="unfinished">檢查更新</translation>
+        <translation>檢查更新</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="172"/>
         <source>Check for updates from the Internet.</source>
-        <translation type="unfinished"></translation>
+        <translation>從網際網路檢查更新。</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="292"/>
         <source>Checking for version updates when the application starts.</source>
-        <translation type="unfinished"></translation>
+        <translation>應用程式啟動時檢查版本更新。</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="304"/>
         <source>GitHub</source>
-        <translation type="unfinished"></translation>
+        <translation>GitHub</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="307"/>
         <source>BKTUS.com</source>
-        <translation type="unfinished"></translation>
+        <translation>BKTUS.com</translation>
     </message>
     <message>
         <location filename="../VersionCheckingModule.cpp" line="312"/>
         <source>Update Checking API:</source>
-        <translation type="unfinished"></translation>
+        <translation>更新檢查 API：</translation>
     </message>
 </context>
 <context>
@@ -90,12 +90,12 @@
     <message>
         <location filename="../UpdateTab.cpp" line="124"/>
         <source>to check for the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>以查詢最新版本。</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="196"/>
         <source>You are using the latest version. No action is required.</source>
-        <translation type="unfinished"></translation>
+        <translation>您已使用最新版本。無需任何操作。</translation>
     </message>
     <message>
         <source>to check for the latest stable version.</source>
@@ -133,12 +133,12 @@
         <location filename="../UpdateTab.cpp" line="164"/>
         <location filename="../UpdateTab.cpp" line="177"/>
         <source>to download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>以下載最新版本。</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="172"/>
         <source>This version is either withdrawn due to critical issues or is an unreleased build. Please stop using it and download the latest version.</source>
-        <translation type="unfinished"></translation>
+        <translation>此版本因重大問題已被撤回，或屬於尚未發佈的版本。請停止使用，並下載最新版本。</translation>
     </message>
     <message>
         <location filename="../UpdateTab.cpp" line="184"/>