feat: add Dashboard with latest card and weight chart

src/components/LatestMeasurementCard.tsx

@@ -0,0 +1,54 @@
+import React from 'react'
+import { View, Text, StyleSheet } from 'react-native'
+import { Measurement } from '../types'
+
+type Props = { measurement: Measurement | null }
+
+const rows: { label: string; key: keyof Measurement; suffix: string }[] = [
+  { label: 'Gewicht', key: 'weight', suffix: 'kg' },
+  { label: 'BMI', key: 'bmi', suffix: '' },
+  { label: 'Vetpercentage', key: 'bodyFatPercentage', suffix: '%' },
+  { label: 'Vetmassa', key: 'fatMass', suffix: 'kg' },
+  { label: 'Spierpercentage', key: 'musclePercentage', suffix: '%' },
+  { label: 'Spiermassa', key: 'muscleMass', suffix: 'kg' },
+  { label: 'Buikvet', key: 'visceralFat', suffix: '' },
+  { label: 'Stofwisseling', key: 'bmr', suffix: 'kcal' },
+]
+
+export default function LatestMeasurementCard({ measurement }: Props) {
+  if (!measurement) {
+    return (
+      <View style={styles.card}>
+        <Text style={styles.emptyText}>Nog geen metingen</Text>
+      </View>
+    )
+  }
+
+  return (
+    <View style={styles.card}>
+      <Text style={styles.title}>Laatste meting</Text>
+      <Text style={styles.date}>{new Date(measurement.measuredAt).toLocaleDateString('nl-NL')}</Text>
+      {rows.map(r => (
+        <View key={r.key} style={styles.row}>
+          <Text style={styles.rowLabel}>{r.label}</Text>
+          <Text style={styles.rowValue}>
+            {typeof measurement[r.key] === 'number'
+              ? (measurement[r.key] as number).toFixed(1)
+              : measurement[r.key]}{' '}
+            {r.suffix}
+          </Text>
+        </View>
+      ))}
+    </View>
+  )
+}
+
+const styles = StyleSheet.create({
+  card: { backgroundColor: '#fff', borderRadius: 12, padding: 16, margin: 16, shadowColor: '#000', shadowOpacity: 0.1, shadowRadius: 8, elevation: 3 },
+  title: { fontSize: 18, fontWeight: '700', marginBottom: 4 },
+  date: { fontSize: 14, color: '#666', marginBottom: 12 },
+  row: { flexDirection: 'row', justifyContent: 'space-between', paddingVertical: 4 },
+  rowLabel: { fontSize: 14, color: '#555' },
+  rowValue: { fontSize: 14, fontWeight: '600' },
+  emptyText: { fontSize: 16, color: '#999', textAlign: 'center', padding: 20 },
+})