re-add system context (ollama#4435)

Author: pdevine

cmd/interactive.go

@@ -292,6 +292,10 @@ func generateInteractive(cmd *cobra.Command, opts runOptions) error {
 			continue
 		case strings.HasPrefix(line, "/clear"):
 			opts.Messages = []api.Message{}
+			if opts.System != "" {
+				newMessage := api.Message{Role: "system", Content: opts.System}
+				opts.Messages = append(opts.Messages, newMessage)
+			}
 			fmt.Println("Cleared session context")
 			continue
 		case strings.HasPrefix(line, "/set"):