Build the user prompt for a single conversation block. Wraps the
source text in delimiters that resist accidental inline-injection
if the conversation contains JSON-looking content.
Parameters
sessionText: string
The conversation text to extract from. Whole
session passed as one block; the model decomposes per turn
internally.
Build the user prompt for a single conversation block. Wraps the source text in delimiters that resist accidental inline-injection if the conversation contains JSON-looking content.