I was fiddling with my front wheel hub (cleaned out and re-packed the bearings), I noticed that the front disc has no clearance to the inside brake pad, there are about 2mm to the pad on outside, but the inside seems like it is dragging. This seems to be the cause of a high pitched quiet squeal while I roll the bike around back and forth... does not seem to have any impact on riding, but I was wondering how one would correct this...

I am thinking that potentially I overtightened the cones ever so slightly, but any looser (I am talking half to quarter turns of the cone) and I get play in the front hub with the wheel attached and the QR tightened (I understand that the QR will tighten the axle and can cause binding)

Is there adjustment for offset on the rotor or caliper?

If you have mechanical disc brakes, the two pads are adjusted separately. The inside one doesn't move in service and is usually set by means of a adjuster screw behind it. Once that's done, you adjust the overall opening and position of the movable pad vial the cable adjuster.

Hydraulics are different because both pads move, and the adjustment method varies by brand.

You should look up any service info for whatever specific brake you have.

Also keep in mind that it's important that the wheel be fully and squarely seated in the fork or frame, otherwise you'll be readjusting everything each time you replace the wheel.

Shim washers work in both cases. ISO mount to adapter, and 6 bolt disc to hub.

backed out the (mechanical) inner pad adjuster?

If Hydraulic Did You Solidly Block Out The caliper with a 'keeper' so the auto pad wear valving does not close on the disc

that was not there, and you touched the brake lever with the wheel Out ???

Now that you mention it....that may be the problem. I may have actuated the brake ever so slightly with the wheel out

OK, you have to remove the wheel and use your fingers to press the shoes all the way back onto the caliper. Then when you reinstall the wheel and apply the brake they should self adjust. However, you might need to reposition the caliper so they center correctly.

Here's how it's done on Shimano brakes. Other are similar but may not be identical (search resetting disc brake pads for more info)

Thank you FBinNY! that sorted it all out. Do I ever feel like a goof...

It's a very common problem. Even if you don't intend to, it's easy to squeeze ot simply bump the lever while the wheel is off. Or if you have kids, they come and "help" screwing you up. That's why Shimano includes (or used to) keepers with their brakes.

I make my own from scrap plastic as thick or slightly thicker than the rotor, and trap them in place with a rubberband, when the wheel will me out for a while, especially if stowing the bike in a car.