ChatApp: need Context length exceeds limit exception

[scsonic]

In other frameworks like llama.cpp and executorch,
when the system prompt exceeds the context length limit, ex: 2048
an exception is raised.

However, ChatApp does not raise an exception.
If the input context is too long, it will display something like:

How and "A. 12, and: or  
own that 5:10  
The (And  
What