Forward sessions through PromptKit requests

internal/framework/llm/promptkit_client.go

@@ -93,13 +93,15 @@ func (c *PromptKitClient) CompleteStructured(ctx context.Context, req contracts.
 	if promptID == "" {
 		return contracts.StructuredCompletionResponse{}, fmt.Errorf("structured completion prompt_id must not be empty")
 	}
+	sessionID := strings.TrimSpace(req.SessionID)
 
 	runReq := promptkit.RunRequest{
 		PromptID:      promptID,
 		PromptVersion: strings.TrimSpace(req.PromptVersion),
 		ProfileID:     strings.TrimSpace(req.ProfileID),
+		SessionID:     sessionID,
 		Inputs:        promptKitInputs(req.Inputs),
-		Vars:          promptKitVars(req),
+		Vars:          promptKitVars(req, sessionID),
 	}
 	prepared, err := c.engine.Prepare(ctx, runReq)
 	if err != nil {
@@ -342,7 +344,7 @@ func promptKitInputs(inputs contracts.LLMInputSet) map[string]promptkit.Artifact
 	return out
 }
 
-func promptKitVars(req contracts.StructuredCompletionRequest) map[string]string {
+func promptKitVars(req contracts.StructuredCompletionRequest, sessionID string) map[string]string {
 	vars := make(map[string]string, len(req.Vars)+1)
 	for key, value := range req.Vars {
 		name := strings.TrimSpace(key)
@@ -351,7 +353,7 @@ func promptKitVars(req contracts.StructuredCompletionRequest) map[string]string
 		}
 		vars[name] = fmt.Sprint(value)
 	}
-	if sessionID := strings.TrimSpace(req.SessionID); sessionID != "" {
+	if sessionID != "" {
 		vars["session_id"] = sessionID
 	}
 	if len(vars) == 0 {