Seems to me that your request is pushing the boundaries of current technology. There have been some small limited run lights available on CPF that have output around 200 lumens. But if you want it to clip onto your pocket or a hat brim, be prepared for very short runtimes. You may be able to get close to one hour on a RCR123 or a 14500 (rechargeable AA) with output close to 150 lumens. These would be small, but not really tiny, but then you're into a rechargeable setup. For small, look to a CR2 or even a AAA powered light, but these are small batteries and at 100 lumens you may only get 15-20 minutes. Look for a CR2 Ion modded with a Q5 emitter. I get maybe 75 lumens, but there is no clip, but its small and easy to hold in the mouth. Also check Orb's website, they offer a number of CR2 lighs but I believe they all require rechargeable batteries. Amilight T5 on a standard 123 is quite nice (do not use rechargeables in this light) - outputs maybe 130 lumens and is very light, but I don't think it comes with a clip. Check this CPF section for the new Endeavor, although it is a bit pricey in titanium (I think he will be offering it in aluminum). You could even look at a Fenix AAA with a Q5, but I don't know if you'd reach 100 lumens on hi, but it is very small, or look to a Lightflux AAA - don't know the output but you could research it on CPF.
take a look at
https://www.candlepowerforums.com/posts/2283078
You must assess your precise needs with what is out there. As JCH79 said, you need to provide more information for folks to steer you better.
Good luck.