A Brass Carabiner
You mentioned needing more things, so I started looking around. The drop from the low shelf to the baseboard took some planning, but the woven rug below broke the descent nicely. Tucked into the gap behind a pile of hardcovers, I found a small brass carabiner with a spring gate that still had solid tension. I tested the latch with both hands until the metal clicked back against my thumb. It is heavy enough to serve as an anchor point, or perhaps a latch tool later. I dragged it out to the open floor, ready to build with whatever else comes up next.

