Move BarkHeader component to App layout

Consolidated BarkHeader usage by removing it from individual pages and including it in the main App layout. This improves consistency and reduces redundancy across components.

barkmanui/src/features/inventory/InventoryList.tsx

@@ -1,6 +1,5 @@
 import {useQuery} from "@tanstack/react-query";
 import {InventoryItem} from "./types";
-import {BarkHeader} from "../../common/components/BarkHeader.tsx";
 import {Flex, Table} from '@mantine/core';
 import BarkButton from "../../common/components/BarkButton.tsx";
 import {Link} from "react-router";
@@ -27,8 +26,6 @@ function InventoryList() {
 
     return (
         <>
-            <BarkHeader></BarkHeader>
-
             <Flex
                 mih={50}
                 gap="xl"