Translations: restore key coverage and fix XML validation

Add English fallbacks for 12 missing keys in 41 language files.
Report all missing keys and XML errors before failing validation.

Run four regression tests in CI. All tests and 43 XML files pass.

Translations/Language.he.xml

@@ -1691,6 +1691,18 @@
     <entry lang="en" key="SYSENC_EFI_LOADER_NOT_TRUSTED_BY_SECUREBOOT">Warning: VeraCrypt could not validate the installed EFI bootloader files against one complete embedded resource set and confirm that all known required signing CAs are present in db and not listed by dbx. Firmware may reject VeraCrypt when Secure Boot is enabled.\n\nBefore booting with Secure Boot enabled, restore the required Microsoft certificates and current dbx as needed, then run VeraCrypt Repair/Reinstall. Do not remove Microsoft Corporation UEFI CA 2011 until db contains both Microsoft UEFI CA 2023 and Microsoft Option ROM UEFI CA 2023 and the actual installed files match VeraCrypt's 2023 set. This check cannot model every image-hash or security-version revocation. Make sure you have an up-to-date VeraCrypt Rescue Disk.</entry>
     <entry lang="en" key="SYSENC_EFI_WINDOWS_LOADER_NOT_TRUSTED_BY_SECUREBOOT">Warning: VeraCrypt could not validate the embedded signature and known-CA compatibility of the Windows Boot Manager it chainloads (bootmgfw_ms.vc). The file may be missing, unreadable, not a Windows Boot Manager, have an unrecognized embedded signer, or use a known signing CA that is absent from db or listed by dbx. The handoff to Windows may fail when Secure Boot is enabled.\n\nComplete or repair the Windows Secure Boot certificate and boot-manager update, keep the VeraCrypt System Favorites service enabled, and run VeraCrypt Repair/Reinstall. Repair also checks Windows' serviced EFI_EX/EFI copies for a compatible current Boot Manager. If Windows cannot start, temporarily disable Secure Boot to recover. Make sure you have an up-to-date VeraCrypt Rescue Disk.</entry>
     <entry lang="en" key="SYSENC_EFI_WINDOWS_LOADER_PCA2011_MIGRATION_NEEDED">Warning: The embedded signature of the Windows Boot Manager used by VeraCrypt (bootmgfw_ms.vc) is still issued by Microsoft Windows Production PCA 2011, although firmware db already contains Windows UEFI CA 2023. Its known CA is currently allowed, but it will no longer start after the PCA 2011 certificate is added to dbx.\n\nDo not apply the PCA 2011 revocation (AvailableUpdates bit 0x80, including combined value 0x280) yet. First complete the Windows 2023 boot-manager update while the VeraCrypt System Favorites service is enabled, then run VeraCrypt Repair/Reinstall so VeraCrypt can import a compatible serviced EFI_EX/EFI copy. Verify the embedded issuer of bootmgfw_ms.vc is Windows UEFI CA 2023 and make sure you have an up-to-date VeraCrypt Rescue Disk.</entry>
+    <entry lang="en" key="MOUNT_SERVICE_INCOMPATIBLE">The service running this volume does not support the requested unmount operation.\n\nUnmount the volume using the version of VeraCrypt that mounted it, then mount it again with this version. Close files using the volume if necessary. Always unmount volumes before upgrading VeraCrypt.</entry>
+    <entry lang="en" key="MOUNT_SERVICE_CLEANUP_FAILED">VeraCrypt could not complete cleanup after a failed mount. The volume may still be accessible.\n\nUnmount the volume in VeraCrypt. If unmounting fails, restart the computer before relying on the volume being locked.</entry>
+    <entry lang="en" key="DISMOUNT_SERVICE_CLEANUP_FAILED">The volume's auxiliary mount has been removed, but VeraCrypt could not confirm that its service has stopped. Encryption keys may still be in memory.\n\nIf the service does not stop, restart the computer before relying on the volume being locked.</entry>
+    <entry lang="en" key="MOUNT_SERVICE_UNAVAILABLE">VeraCrypt could not contact or verify the volume service.\n\nIf this occurred while dismounting, close files using the volume and retry. If cleanup cannot be confirmed, restart the computer before relying on the volume being locked.</entry>
+    <entry lang="en" key="VOLUME_DISCOVERY_FAILED">VeraCrypt could not verify all volume information. A volume service or disk image may be unavailable or inaccessible.\n\nAny volumes shown are only the entries VeraCrypt could verify. Wait for pending disk operations to finish and retry. An incomplete list does not confirm that all volumes are dismounted.</entry>
+    <entry lang="en" key="VOLUME_IN_USE">The volume is in use. Close files and applications using it, then retry unmounting.</entry>
+    <entry lang="en" key="OPERATION_TIMED_OUT">The operation did not finish in time. Check the volume's status before retrying.</entry>
+    <entry lang="en" key="VOLUME_STATUS_UNKNOWN">Status unavailable</entry>
+    <entry lang="en" key="VOLUME_IMAGE_ABSENT">Image detached; unmount to finish</entry>
+    <entry lang="en" key="VOLUME_DISCOVERY_PENDING">Refreshing volume status…</entry>
+    <entry lang="en" key="VOLUME_DISCOVERY_STALLED">Volume status unavailable; retrying…</entry>
+    <entry lang="en" key="VOLUME_DISCOVERY_PARTIAL">Some volume information is unavailable; retrying…</entry>
   </localization>
   <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified">
     <xs:element name="VeraCrypt">