fix(webui): disable open plugin UI button when plugin is deactivated

Prevent navigation to a disabled plugin's WebUI page which would
result in an error.

Author: lxfight

dashboard/src/components/shared/ExtensionCard.vue

@@ -339,6 +339,7 @@ const openWebui = () => {
               size="small"
               variant="tonal"
               color="primary"
+              :disabled="!extension.activated"
               @click.stop="openWebui"
             ></v-btn>
           </template>