final: refactor for removal of system package and reduction of interactions to state package

State query command has been moved to main where it belongs, "system" information are now fetched in app.New and stored in *App with accessors for relevant values. Exit (cleanup-related) functions are separated into its dedicated "final" package.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

internal/final/prepare.go

@@ -0,0 +1,20 @@
+package final
+
+import "os/user"
+
+var (
+	u   *user.User
+	uid int
+
+	runDirPath string
+)
+
+func Prepare(val user.User, d int, s string) {
+	if u != nil {
+		panic("final prepared twice")
+	}
+
+	u = &val
+	uid = d
+	runDirPath = s
+}