Safety of hard wiring cable lighting intended for halogen bulbs in a circuit with LED dimmer switch
Back when every lamp was an incandescent bulb, things were simple.  Then Mr. Tesla came along...   In this day and age, you can't just slapdash random hardware together and expect it to work together.  

The dimmer is not listed to drive a DC power supply, is therefore not legal to use with it, and in any case, is unlikely to play nice.  

Some DC power supplies are multi-voltage. Dimming is completely ineffective on them, they see dimming as lower voltage, and draw more current to compensate, potentially overloading the dimmer. 

If you want to go Low voltage lighting, you will need to get a power supply compatible with whatever LEDs you expect to use in the future, and then get a dimmer designed to dim those LEDs and halogens.