TODO: implementing the manual history tracking fix in StatefulExecutorBase

[zsogitbe]

Description

PR: #1373

Explanation: I am holding off on implementing the manual history tracking fix in this PR for StatefulExecutorBase. Rebuilding the KV cache manually for models that don't support native memory shifting is highly complex and risks silent state corruption, especially when dealing with session caching and multimodal inputs. Keeping the ContextOverflowException guard as-is forces the calling application to handle the overflow gracefully (e.g., starting a new chat) rather than risking a desynced model state. We can revisit this if we see high user impact, but stability comes first.

[aropb]

I use context shifting for multimodal models, it is important to preserve input prompt, and the response can be shifted.