`LoadCredential` naming a missing path is fatal at unit start, and this hive's
secret is minted by authelia's first-boot generator inside its own container —
nothing orders a host unit against that.
nixpkgs sets `Restart = "always"` on the collector with no `RestartSec`, so
that failure is instant: the unit burns systemd's 5-starts-in-10s allowance in
well under a second, lands in `start-limit-hit`, and stops retrying entirely.
`Restart = always` reads like it makes this self-healing and does the opposite
— a slow-failing unit retries until the secret appears, a fast-failing one
exhausts its limit before the thing it waits for can exist.
A oneshot converts the fast failure into a slow one, which is what that restart
policy is actually good at. Copied from `hive-forge-oidc-secret.service`, which
already solves this for the forge: bounded wait, then fail loudly naming the
file — never skip, because a skip yields a collector that starts and ships
nothing.
`TimeoutStartSec` exceeds the wait on purpose: `DefaultTimeoutStartSec` is 90s
and would kill the unit before it could emit that message.
The ordering against authelia's container is conditional — on a hive that does
not host the provider the secret is operator-provided, and naming a unit that
does not exist orders nothing, silently. The wait itself still applies there,
so a file that arrives late is tolerated rather than fatal.