AIAgentOverrideSystemPrompt Method

Replaces the leading system message in Messages with prompt. If prompt is null or whitespace the existing system message (if any) is simply removed. Call this before Chat(String, ICancelOperation, ReportExecutionLog, ReportExecutionLog, Int32, ActionString) to inject a parameter-driven system prompt that overrides the one from EffectiveSystemPrompt (kept until Clear: the configuration prompt is no longer re-applied at each turn).

public void OverrideSystemPrompt(
	string prompt
)