Auto-bundle and install all lib deps

[jacobkahn]

Install Flashlight deps to get to truly one-line install — for now, this is just ArrayFire.

Approach would be either:
1a. Bundle ArrayFire libs as standalone for each platform (i.e. libaf* as a platform-specific npm package).
1b. Dynamically download libs at runtime as needed -- can do more distro-specific detections this way (i.e. run uname -a)
2. Hope things work per distro glibc versions — there will be pain here at the beginning, but do the best we can.
3. Resolve LD_LIBRARY_PATH and equivalents to find libs at Bun dlopen/ffi time.