pos_ticket_homepro/template.xml

<openerp>
    <data>
        <template id="pos_ticket_homepro_assets_backend" name="pos_ticket_homepro_assets_backend" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <script src="/pos_ticket_homepro/static/src/js/main.js" type="text/javascript"></script>
                <script src="/pos_ticket_homepro/static/src/js/customer.js" type="text/javascript"></script>
                <script src="/pos_ticket_homepro/static/src/js/screen.js" type="text/javascript"></script>
            </xpath>
        </template>
    </data>
</openerp>