Add customizable system prompt

agent/options.go

@@ -30,6 +30,8 @@ type options struct {
 	kbResults                                         int
 	ragdb                                             RAGDB
 
+	systemPrompt string
+
 	// callbacks
 	reasoningCallback func(ActionCurrentState) bool
 	resultCallback    func(ActionState)
@@ -110,6 +112,13 @@ func WithRAGDB(db RAGDB) Option {
 	}
 }
 
+func WithSystemPrompt(prompt string) Option {
+	return func(o *options) error {
+		o.systemPrompt = prompt
+		return nil
+	}
+}
+
 func WithLLMAPIURL(url string) Option {
 	return func(o *options) error {
 		o.LLMAPI.APIURL = url