Fix duplicate deep chat intro message after clearing history on front-end themes

Attached a static ai--2025-04-06--3517604--mr-544.patch file.
To be used with Composer Patches

Reviewed and works for me. Solution also seems appropriate.

Tested with 1.1.xalso, the issue exists, and the changes suggested by @rajab natshah fix the issue. Looks good to be merged.