hst/config: move container fields from toplevel

This change also moves pd behaviour to cmd/hakurei, as this does not belong in the hst API.

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

internal/app/dispatcher.go

@@ -45,9 +45,6 @@ type syscallDispatcher interface {
 	// evalSymlinks provides [filepath.EvalSymlinks].
 	evalSymlinks(path string) (string, error)
 
-	// lookPath provides exec.LookPath.
-	lookPath(file string) (string, error)
-
 	// lookupGroupId calls [user.LookupGroup] and returns the Gid field of the resulting [user.Group] struct.
 	lookupGroupId(name string) (string, error)
 
@@ -81,8 +78,6 @@ func (direct) tempdir() string                            { return os.TempDir()
 
 func (direct) evalSymlinks(path string) (string, error) { return filepath.EvalSymlinks(path) }
 
-func (direct) lookPath(file string) (string, error) { return exec.LookPath(file) }
-
 func (direct) lookupGroupId(name string) (gid string, err error) {
 	var group *user.Group
 	group, err = user.LookupGroup(name)