Folding bike cleaning
It would take a lot of cleaning to wear away the folding mechanisms on a Dahon. Unless you're cleaning your bike with steel wool and an angle grinder, you have very little to worry about. However, as you likely know, not cleaning your bike can result in excessive wear. The good news is that, since this is a single-speed bike, you have less to clean. 

While folders do get dirtier than other bikes, because they're lower to the ground, cleaning one isn't all that different from cleaning a non-folding bike, with a few differences: 

In general, you want to get the dirt off (including any road salt) or grit or sand, clean the drivetrain, then relube it. Make sure to rinse off any degreaser before relubing. Since a folding frame has more points of entry, you might want to take more care to avoid getting anything inside the frame - or spend a little time investigating to see if you have any dirt or grit in there. 

Attacking the dirt and road grime with warm soapy water and then rinsing it off will be your best strategy. There's some controversy about whether or not citrus degreaser is bad for a bike's paint job, but I use it for stubborn bits of dirt and make sure to rinse it off thoroughly. I would avoid high-pressure water, or at the very least, keep it away from the bearings and folding parts. 

I'm not sure what that plastic covering is on the chain, but it looks like it's there to protect it, which should make your job easier. You'll still want to remove the chain from time to time and clean it. On my Dahon Curve, I do it by removing the rear wheel and soaking the chain overnight in diluted degreaser, then rinsing the chain thoroughly. (The rear hub on a Curve can be a little finicky to put back on, but for reasons involving the internal hub. That's not an issue with the Uno, since it's a singlespeed.)

Cleaning smaller wheels can be a little difficult, because the spaces between the spokes and the rim are so small. However, there's less area to cover, so that evens out. 

The folding parts on a Dahon include the frame hinge joint, the handlebar pillar, the seat post, and the stem hinge. They don't have any particular instructions for cleaning (soap and water will do a fine job), but you do want to make sure those are maintained.