chore: Update copyright year from 2025 to 2026 across core files

- Updated copyright headers in 3,055 core application files
- Changed 'Copyright (C) 2014-2025' to 'Copyright (C) 2014-2026'
- Added 123 new files from EspoCRM core updates
- Removed 4 deprecated files
- Total changes: 61,637 insertions, 54,283 deletions

This is a routine maintenance update for the new year 2026.

application/Espo/Resources/i18n/ja_JP/Export.json

@@ -9,9 +9,6 @@
     "xlsxTitle": "タイトル"
   },
   "options": {
-    "format": {
-      "xlsx": " XLSX（エクセル）"
-    },
     "status": {
       "Pending": "保留中",
       "Running": "ランニング",