Add the whole api stack for weight

frontend/src/lib/components/Weight/EmptyWeightComp.svelte

@@ -0,0 +1,47 @@
+<script lang="ts">
+	import { toast } from 'svelte-sonner'
+	import type { Err } from '$lib/types'
+	import { type Weight, WeightService } from '$lib/database/weight'
+	import { weightStore } from '$lib/store/weight/weightStore'
+	import { RefreshStores } from '$lib/utils'
+
+	let item: Weight = {
+		weight: 0
+	}
+	let weight: string | null = null
+
+	async function update(event: KeyboardEvent & { currentTarget: (EventTarget & HTMLTableCellElement) }) {
+		if (!weight) return
+		weight = weight.trim()
+
+		if (event.key == 'Enter') {
+			event.preventDefault()
+			item.weight = parseFloat(weight)
+
+			const [dbRow, err]: [Weight, Err] = await WeightService.Create(item)
+			weight = ''
+
+			if (err) {
+				toast.error(err)
+				return
+			}
+			RefreshStores()
+		}
+	}
+</script>
+
+<template>
+	<tr class="border-b border-gray-200 dark:border-gray-700 text-lg font-bold">
+		<th class="px-6 py-4 font-medium text-gray-900 whitespace-nowrap bg-gray-50 dark:text-white dark:bg-gray-800"
+		    scope="row">
+		</th>
+		<td bind:innerText={weight}
+		    class:border-[3px]={!weight}
+		    class:border-red-600={!weight}
+		    class="px-6 py-4 overflow-hidden"
+		    contenteditable="true"
+		    autofocus
+		    on:keydown={update}>
+		</td>
+	</tr>
+</template>