feat: implement legacy config auth storage and core api

chfs-ng/internal/auth/auth_test.go

@@ -0,0 +1,20 @@
+package auth
+
+import "testing"
+
+func TestParseRules(t *testing.T) {
+	m, err := ParseRules([]string{"::r|admin:secret:rw:private:d"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !m.Guest.Mask.HasRead() || m.Guest.Mask.HasWrite() {
+		t.Fatal("guest mask")
+	}
+	a := m.Accounts["admin"]
+	if a == nil || !a.Mask.HasWrite() || a.Mask.HasDelete() {
+		t.Fatal("admin mask")
+	}
+	if got := a.MaskFor("private/x"); !got.HasDelete() {
+		t.Fatalf("subrule=%v", got)
+	}
+}