internal/validate: relocate from app

These are free of the dispatcher from internal/app. This change relocates them into their own package.

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

internal/validate/sysconf_test.go

@@ -0,0 +1,21 @@
+package validate_test
+
+import (
+	"testing"
+
+	"hakurei.app/internal/validate"
+)
+
+const (
+	_POSIX_LOGIN_NAME_MAX = 9
+)
+
+func TestSysconf(t *testing.T) {
+	t.Parallel()
+
+	t.Run("LOGIN_NAME_MAX", func(t *testing.T) {
+		if got := validate.Sysconf(validate.SC_LOGIN_NAME_MAX); got < _POSIX_LOGIN_NAME_MAX {
+			t.Errorf("sysconf(_SC_LOGIN_NAME_MAX): %d < _POSIX_LOGIN_NAME_MAX", got)
+		}
+	})
+}