feat(linstor): support DRBD-less substrates beyond Talos #4092

drbd.enabled=false exists for substrates whose kernel cannot run DRBD, but today it only works together with talos.enabled=true, and the chart refuses the other combination at render time.

The reason is that the flag removes the drbd-logger sidecar and nothing else. The satellite DaemonSet also carries two DRBD-only initContainers that piraeus-operator contributes unconditionally, drbd-module-loader and drbd-shutdown-guard, and the only configuration that deletes them is satellites-talos.yaml, gated on talos.enabled. On generic Linux without the module the satellite therefore never becomes Ready, which is the state the flag exists to avoid, so refusing is currently better than rendering it.

Making it general means moving those two deletions and the lib-modules, usr-src, run-systemd-system, run-drbd-shutdown-guard and systemd-bus-socket volumes out from under talos.enabled into the drbd.enabled=false patch, and covering the corner in packages/system/linstor/tests/satellites_test.yaml. isp-full-generic is the shipped variant that sets talos.enabled=false, so that is the configuration to validate against.

Low priority on purpose. Nobody runs drbd.enabled=false in production, and the people who do set it have a specific reason and accept the rough edges that come with it. The current render-time refusal names both flags, so the failure mode is a clear error rather than a satellite that silently never comes up.