The contact submenu's reset-path action set out_path_len = 0, which
means "direct, 0 hops" — formatHopCount rendered the contact as
"direct" and sendMessage would still try direct send. Use
OUT_PATH_UNKNOWN (0xFF) so the next DM floods and rediscovers the
path. Also schedule a contacts flush (markContactsDirtyPublic) so
the reset survives reboot — previously the change was in-memory only.