fix(fitness): update slug + rename measureSlug → checkinSlug

Four pages had their own hardcoded `measureSlug = lang === 'en' ? 'measure' : 'messen'`
derived — all still pointing at the old route. Bumped the value to
check-in / erfassung and renamed the variable so future drift of
this kind is easier to grep for.

Affects links from:
- /fitness/check-in → body-parts card, inline "Edit all fields"
- body-parts flow → back / cancel navigation
- full-edit page → save / delete navigation
- /fitness/stats/history/[part] → "measure this now" CTA

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.46.10",
+	"version": "1.46.11",
 	"private": true,
 	"type": "module",
 	"scripts": {

src/routes/fitness/[checkin=fitnessCheckIn]/+page.svelte

@@ -16,7 +16,7 @@
 	);
 
 	const lang = $derived(detectFitnessLang($page.url.pathname));
-	const measureSlug = $derived(lang === 'en' ? 'measure' : 'messen');
+	const checkinSlug = $derived(lang === 'en' ? 'check-in' : 'erfassung');
 	import { getWorkout } from '$lib/js/workout.svelte';
 	import PeriodTracker from '$lib/components/fitness/PeriodTracker.svelte';
 
@@ -529,7 +529,7 @@
 			</div>
 		</div>
 
-		<a class="bp-card" href="/fitness/{measureSlug}/body-parts">
+		<a class="bp-card" href="/fitness/{checkinSlug}/body-parts">
 			<div class="bp-figure" aria-hidden="true">
 				<div class="muscle-base">{@html bpFrontSvg}</div>
 				<svg class="dot-overlay" viewBox="0 {BP_VIEW_TOP} 660.46 {BP_VIEW_H}" preserveAspectRatio="xMidYMid meet">
@@ -621,7 +621,7 @@
 										<span class="edit-unit">%</span>
 									</div>
 									<div class="edit-actions">
-										<a class="edit-more" href="/fitness/{measureSlug}/edit/{m._id}" aria-label={t('edit_measurement', lang)}>
+										<a class="edit-more" href="/fitness/{checkinSlug}/edit/{m._id}" aria-label={t('edit_measurement', lang)}>
 											<Pencil size={11} />
 											<span class="edit-more-label">{lang === 'en' ? 'Edit all fields' : 'Alle Felder bearbeiten'}</span>
 											<ChevronRight size={11} />

src/routes/fitness/[checkin=fitnessCheckIn]/body-parts/+page.svelte

@@ -15,7 +15,7 @@
 	let { data } = $props();
 
 	const lang = $derived(detectFitnessLang($page.url.pathname));
-	const measureSlug = $derived(lang === 'en' ? 'measure' : 'messen');
+	const checkinSlug = $derived(lang === 'en' ? 'check-in' : 'erfassung');
 
 	/** @typedef {{ key: string, labelKey: string, img: string | null, paired: boolean, tipKey: string, dbSingle?: string, dbLeft?: string, dbRight?: string }} Step */
 
@@ -241,7 +241,7 @@
 			}
 			if (res.ok) {
 				toast.success(lang === 'en' ? 'Measurement saved' : 'Messung gespeichert');
-				await goto(`/fitness/${measureSlug}`);
+				await goto(`/fitness/${checkinSlug}`);
 			} else {
 				const err = await res.json().catch(() => null);
 				toast.error(err?.error ?? 'Failed to save measurement');
@@ -251,7 +251,7 @@
 	}
 
 	function exit() {
-		goto(`/fitness/${measureSlug}`);
+		goto(`/fitness/${checkinSlug}`);
 	}
 
 	// ----- Chart -----

src/routes/fitness/[checkin=fitnessCheckIn]/edit/[id]/+page.svelte

@@ -9,7 +9,7 @@
 	import DatePicker from '$lib/components/DatePicker.svelte';
 
 	const lang = $derived(detectFitnessLang($page.url.pathname));
-	const measureSlug = $derived(lang === 'en' ? 'measure' : 'messen');
+	const checkinSlug = $derived(lang === 'en' ? 'check-in' : 'erfassung');
 
 	let { data } = $props();
 	// svelte-ignore state_referenced_locally
@@ -73,7 +73,7 @@
 				body: JSON.stringify(buildBody())
 			});
 			if (res.ok) {
-				await goto(`/fitness/${measureSlug}`);
+				await goto(`/fitness/${checkinSlug}`);
 			} else {
 				const err = await res.json().catch(() => null);
 				toast.error(err?.error ?? 'Failed to save measurement');
@@ -88,7 +88,7 @@
 		try {
 			const res = await fetch(`/api/fitness/measurements/${m._id}`, { method: 'DELETE' });
 			if (res.ok) {
-				await goto(`/fitness/${measureSlug}`);
+				await goto(`/fitness/${checkinSlug}`);
 			} else {
 				const err = await res.json().catch(() => null);
 				toast.error(err?.error ?? 'Failed to delete measurement');

src/routes/fitness/[stats=fitnessStats]/[history=fitnessHistory]/[part]/+page.svelte

@@ -9,7 +9,7 @@
 
 	const lang = $derived(detectFitnessLang($page.url.pathname));
 	const statsSlug = $derived(lang === 'en' ? 'stats' : 'statistik');
-	const measureSlug = $derived(lang === 'en' ? 'measure' : 'messen');
+	const checkinSlug = $derived(lang === 'en' ? 'check-in' : 'erfassung');
 	const card = $derived(data.card);
 
 	const historyAsc = $derived(
@@ -169,7 +169,7 @@
 	{#if !hasData}
 		<div class="empty">
 			<p>{t('no_measurements_yet', lang)}</p>
-			<a class="cta" href="/fitness/{measureSlug}/body-parts">
+			<a class="cta" href="/fitness/{checkinSlug}/body-parts">
 				<Ruler size={16} /> {t('measure_body_parts', lang)}
 			</a>
 		</div>