BV front bike light modification

As an ultra-long-distance cyclist, I was frustrated by my bike lights running out of battery mid-journey. The final straw came when the police nearly fined me after my rear light lost power just 30 minutes before I got home, at the end of a 25-hour ride. That experience led me to build a solution with a much longer battery life.

This project reuses an existing [front light](https://bv-usa.com/products/bv-bike-safety-lights-usb-rechargeable-led-bike-light-bicycle-lamp-set) and adds a housing that fits an 18650 battery with much greater capacity. All original parts can be reused, it is just a larger body.

#### Print Settings
* Layer height: 0.3 mm or lower
* Infill: 30%
* Material: ideally, use a durable, water- and UV-resistant filament such as ASA. I used some leftover NYLON-CF mix.
* Supports: not required for the top, but the body needs something either soluble or easily detachable, such as the organic supports that PrusaSlicer can generate

#### Bill of Materials
* 1× [BV LED ligh