* fix(volume): write state.pb into a real dir when -dir.idx is unset
When -dir.idx is not set, NewStore passed the empty default to
NewState, making the state.pb path resolve to a relative "state.pb"
against the process CWD. Under systemd (where CWD is typically /),
this caused "open state.pb: permission denied" for operations such
as `volumeServer.state -maintenanceOn`, even though the configured
user owned the data dirs.
Fall back to the first disk location's IdxDirectory so state.pb lives
next to the volume data, consistent with other per-server artifacts.
Fixes#9173
* fix(volume): always resolve state.pb dir via first disk location
Use s.Locations[0].IdxDirectory unconditionally when a location
exists so state.pb inherits the same resolution (~ expansion and
empty-idxFolder fallback) already applied for the .idx files.
Fall back to util.ResolvePath(idxFolder) in the location-less case
so a relative or tilde-prefixed -dir.idx is still normalized.
Addresses PR feedback on #9178.
Chris LuandGitHub
45ba71a189