### What problem does this PR solve?
Feat: Delete useless request hooks. #10427
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
This PR closing feature request #11286.
It implements ability to choose the background theme of the _Full screen
chat_ which is Embed into webpage.
Looks like that:
<img width="501" height="349" alt="image"
src="https://github.com/user-attachments/assets/e5fdfb14-9ed9-43bb-a40d-4b580985b9d4"
/>
It works similar to `Locale`, using url parameter to set the theme.
if the parameter is invalid then is using the default theme.
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Your Name <you@example.com>
### What problem does this PR solve?
Add a chat widget. I'll probably need some assistance to get this ready
for merge!
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
Co-authored-by: Mohamed Mathari <nocodeventure@Mac-mini-van-Mohamed.fritz.box>
### What problem does this PR solve?
Feat: Translate the fields of the embedded dialog box on the agent page
#3221
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
Feat: Displays the embedded page of the chat module #3221
Feat: Let the agen operator support the selection of tts model #3221
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
