Alright guys I figured it out. Turns out the problem was two parts. One part bad bulb, one part bad owner lol.
Posting this process so if someone else is in the same situation they can use this as a guide to figure it out.
Was reading no voltage at any of the headlight terminals. Was reading battery voltage at the fuse. Thinking to myself, alright then the problem must be between those two points, I decided to chase the wires back down the harness. Out of sheer luck I started with the green wire. I made a small incision in the rubber harness that runs along the backbone of the frame to see where that green headlight wire was running to. I couldn't find it anywhere.
Strange, I thought, because it must be running to the power somewhere. I went back to the headlight area and figured I'd chase it from the very beginning to find the route. Turns out, it tucked into the same harness that all the other wires did, but it does a 180 and comes right back out! Where does it lead to? That blue block I removed some wires from.
Pulled out the phone for the old google search tactic. Searching "roadstar headlight wiring" I came upon this confusing (to me at least) looking diagram.
Reminding myself that it's either figure this diagram out or never ride at night again, I took a closer look to find anything I could use as a baseline as to where I was in this mess of wires. Bottom left area labeled headlight is where we're at for this particular job. I see the green yellow and black wires that match the block I'm looking at. Green wire is what I'm seeing routing back into a blue block that goes nowhere. Not good. What's the green wire labeled? "Lo beam." Ahh, that would explain the problem here lol.
Whatever was attached to that blue fuse block (that I removed when I changed the bulb because it went to nothing) must have done a 180 of it's own and gone back into the main
harness leading to power and by removing it I opened the circuit.
Looking at the diagram further, I see that the green wire makes a connection to a red and yellow wire which then takes it back to the headlight fuse. Ok, there's two of those in this empty white socket connector.
Using a spare piece of wire, I stuffed one end into the green wire slot on the blue block, and the other end into one of the red and yellow wire slot on the white block. Testing the green wire for voltage still reads zero. No luck. Repeated the process for the other red yellow wire slot in the white block and voila! I get battery voltage on the green wire again! In the picture below you can see the testing method in action, that small yellow wire between the white and blue blocks was the testing wire.
In realizing that I had found the proper connection I needed, I snipped both wires out of their fuse blocks and twisted them together with some electrical tape over top of them. I'll do a proper solder connection with heat shrink once I get the bike over to my buddies garage, but there's only so much you can do when it's night time and your bike is in a parking lot in pieces lol.
But alls well that ends well, and I took her out for a spin with my new headlight shining as bright as ever, feeling proud of myself for finding the problem, and happy that I started with that green wire! The next project will be to replace the headlight entirely with a smaller one, and to remove all those extra wires from the headlight bucket.
More on that in the future, off to ride for now.