internal/pkg: set container scheduling policy

This is not as necessary as it was for nix, since internal/pkg only unblocks exclusive artifacts one at a time. Still, this is useful when running alongside an unprivileged music player which cannot set itself to a higher priority.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/exec.go

@@ -23,7 +23,7 @@ import (
 	"hakurei.app/message"
 )
 
-// AbsWork is the container pathname [CureContext.GetWorkDir] is mounted on.
+// AbsWork is the container pathname [TContext.GetWorkDir] is mounted on.
 var AbsWork = fhs.AbsRoot.Append("work/")
 
 // ExecPath is a slice of [Artifact] and the [check.Absolute] pathname to make
@@ -39,6 +39,9 @@ type ExecPath struct {
 	W bool
 }
 
+// SchedPolicy is the [container] scheduling policy.
+var SchedPolicy int
+
 // PromoteLayers returns artifacts with identical-by-content layers promoted to
 // the highest priority instance, as if mounted via [ExecPath].
 func PromoteLayers(
@@ -408,6 +411,7 @@ func (a *execArtifact) cure(f *FContext, hostNet bool) (err error) {
 	z.ParentPerm = 0700
 	z.HostNet = hostNet
 	z.Hostname = "cure"
+	z.SchedPolicy = SchedPolicy
 	if z.HostNet {
 		z.Hostname = "cure-net"
 	}