Offline wheels for aarch64 / Bookworm

Place bless and its dependencies as .whl files here so device-install.sh can run:

python3 -m pip install --no-index --find-links . bless

Example (on a matching arm64 Bookworm host with network):

pip download bless -d collector/wheels

Without wheels, install falls back to pip install -r requirements.txt (requires internet on the device).