Localisation failures: UI elements remain in English when changing language or trying to "live translate"

[aphilop]

Describe the bug

Users who have switched their Uwazi interface to a supported language other than English can experience translation failures that make key UI elements appear in English instead of their selected language. This seems to affect core functionality including dropdown menus, form fields, accessibility features, and in some cases also the ability to "live translate". An AI-supported audit revealed several issues that are documented in the attached report.

missing-translation-keys-report.md

To Reproduce

Steps to reproduce the behavior:

1. Go to Settings > Collection
2. Switch to "Live translate"
3. Observe that several UI terms can't be translated ("Custom landing page", "Map API key", "Map Layers", etc.)

Expected behavior

• When changing the UI language into a supported one, all UI elements must be displayed in the selected language (assuming that there are corresponding translations for all translation keys)
• When activating "Live translation", the user must be able to translate all UI elements that are "allowed" to be translated.
• Screen reader users should hear interface announcements in their selected language

Screenshots

Device (please select all that apply)
-All

Browser
Safari 26.1 on macOS Sequioa 15.7.2