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/metadata/entityDefs/AppSecret.json

@@ -6,7 +6,8 @@
             "required": true,
             "pattern": "[a-zA-Z]{1}[a-zA-Z0-9_]+",
             "index": true,
-            "tooltip": true
+            "tooltip": true,
+            "copyToClipboard": true
         },
         "value": {
             "type": "text",