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.

client/res/templates/settings/fields/currency-rates/edit.tpl

@@ -8,6 +8,7 @@
                 data-currency="{{@key}}"
                 value="{{./this}}"
                 style="text-align: right;"
+                readonly="readonly"
             >
         </span>
         <span class="input-group-addon radius-right" style="width: 22%">{{../baseCurrency}}</span>