Nice concept. I think it is, however, a very difficult thing to achieve with Hermetic magic. Hermetic magic is pretty flexible; you can summon spirits, conjure towers from the earth, make stuff blow up real good, but being just plain lucky is going to be pretty tricky to achieve.
One thing to bear in mind also is that you might want a concept that can grow over time. Just being lucky is good, but you might want an idea of how that could develop from that starting point.
However... Here's how I would look at it (again, just taking the Hermetic option). You fake the luck.
Specialise in Intellego magic to the point that you can cast a number of low-level Intellego spells across a range of Forms. For instance, it's a level 5 Intellego Terram spell to learn the exact weight of an object just by touching it, or level 15 just by looking at it. The same applies to knowing its weakest point, or how much weight it could bear, for instance.
It's a level 20 spell to read a person's surface thoughts by looking them in the eye, which is pretty handy for making those educated guesses about what they want or where they're going.
And if you want to manipulate the environment, you might take some low-level Rego spells so you can tip the dice your favour, ensure the burning torch falls away from the hay stack, or the arrow snags the bow as it leaves it.
If you want to appear as though these things are happening without your involvement then take the Subtle Magic Virtue and Quiet Magic, both minor. Consider The Gentle Gift as that means people are less likely to jump to the conclusion that the screwy thing that just happened was down to you. Gentle Gift is a major Virtue.
Of course, chances are you also want to take the Luck Virtue too.
The good thing about taking that route is that you can always improve your Arts such that you are able to quietly and subtly affect more things or learn more information, all in the name of making your path in the world a little more predictable - making sure the world is on your side.
You could also take the Mythic Blood Virtue option and take a level 15 effect that you invoke with no words or gestures. For a level 15 (and I'm cheating a little and using Hedge Magic: Revised Edition), you could take a spell that affects you the caster for Sun Duration and grants a +3 Bonus to Luck rolls (as defined by the Storyguide). Mythic Blood is major, so it may clash with Gentle Gift. Not sure.
I'm sure others will be able to suggest more builds, but that's my initial take on the concept. As I said, a very nice concept to play, but devilishly difficult with just Hermetic magic.