The hosted installer only ever chose the x86_64 bundle, so a 32-bit field
laptop running the public one-liner failed with "no compatible bundle" even
though fingerprint-agent v1.5.0 publishes fpagent-<version>-linux-i386.tar.gz.
Resolve the host architecture from uname -m (x86_64 or i386, else fail before
any download), then prefer -ubuntu-<codename>-<arch>.tar.gz and fall back to
-linux-<arch>.tar.gz. The version regex now derives the git hash for every
supported architecture, so a 32-bit install records and reports it too.
The help text matches the bundle installer: the systemd service and the
self-update timer are on by default, with --no-service, --no-updates and
--update-base documented.