I'd look at the Fenix BC30 v2.
Battery life: infinite. Just bring as many spare 18650s as you need. I'd get these batteries and this charger if you're in the US. The charger also serves as a USB powerbank and a way to carry spares.
It does a stable 600 lumens for 6 hours so you might not need spares (but you do need to buy at least a pair of batteries and a charger separately).
Seconded. I have an older, single cell version of this light (BC-21R) and it is nice. I like the beam and that it has a built in charger (in fact the only 18650 charger I can find right now: I've misplaced my usual one).
I'm not that crazy about its handlebar mount or UI, but I think they have gone to a better handlebar mount in newer models, and the UI for a bike light is not that important since you don't use the controls nearly as often as you would those of a flashlight.
There is another thread here with a few suggestions in the comments: https://lemmy.world/post/660260
By the way, if you order from fenix-store, try discount code APP20.
Portable illumination
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