I don’t know well how to work “inside” svg (I just create svg in another app as graphic elements, never thinking in it as a more interactive element).
But just applying some logic, you need to be attention to this: an internal link is a special class (class="internal-link"). So, you need to add a class or - I’m note sure - changing the “href” to an obsidian app url format - similar to “obsidian://open?vault=…”