fix(packages): restrict limited owner package access (#39043)

Apply restricted-viewer visibility rules when resolving package access.

---------

Co-authored-by: silverwind <me@silverwind.io>

services/context/package_test.go

@@ -0,0 +1,26 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package context
+
+import (
+	"testing"
+
+	"gitea.dev/models/perm"
+	"gitea.dev/models/user"
+	"gitea.dev/modules/structs"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDeterminePackageAccessModeForLimitedOwner(t *testing.T) {
+	owner := &user.User{ID: 1, Visibility: structs.VisibleTypeLimited}
+
+	accessMode, err := determineAccessMode(&Base{}, owner, &user.User{ID: 2, IsActive: true})
+	assert.NoError(t, err)
+	assert.Equal(t, perm.AccessModeRead, accessMode)
+
+	accessMode, err = determineAccessMode(&Base{}, owner, &user.User{ID: 3, IsActive: true, IsRestricted: true})
+	assert.NoError(t, err)
+	assert.Equal(t, perm.AccessModeNone, accessMode)
+}