energy stored in circuit under steady circuit
The energy stored in the circuit in steady-state is not zero even though the frequency is zero, because the capacitors will be charged.  As you correctly stated in your question you can remove the caps to determine the voltage drops across the resistors.  You are also correct that only the resistors will dissipate energy, but the caps will stay charged, therefore storing energy.

Once you determine the voltage across the resistors, you can put the caps back in and assume they will be charged to the same level as the voltage across the respective connection points.  Then use the energy formula E = 0.5CV^2.