fix: sync refactor — fix 6 bugs + cache refresh na sync

- setDeletedAt update nu ook updatedAt (bug 2)
- getAllMeasurements filtert deletedAt IS NULL, nieuwe getAllMeasurementsForSync voor sync
- mergeMeasurements detecteert server deleted:true → deletedAt (bug 1)
- syncAll: pull-push split met remoteUpdatedMap, geen double-push (bug 3)
- hard delete alleen na API-succes (bug 4)
- DashboardScreen: refreshCache() na syncAll zodat UI niet op Laden blijft hangen
- deleteMeasurement() dead code verwijderd (bug 5)
- tests: 3 nieuwe testcases voor deleted → deletedAt mapping, 15/15 pass

src/screens/HistoryScreen.tsx

@@ -2,6 +2,7 @@ import React, { useCallback, useState } from 'react'
 import { View, FlatList, StyleSheet, Text, RefreshControl, TouchableOpacity, Alert } from 'react-native'
 import { useFocusEffect } from '@react-navigation/native'
 import { initDatabase, getAllMeasurements, setDeletedAt, removeMeasurement } from '../database/db'
+import { removeFromCache } from '../store/measurementStore'
 import { Measurement } from '../types'
 import { createApi } from '../sync/api'
 import { getApiConfig } from './SettingsScreen'
@@ -64,13 +65,17 @@ export default function HistoryScreen({ navigation }: Props) {
           onPress: async () => {
             await initDatabase()
             await setDeletedAt(m.id)
+            removeFromCache(m.id)
             try {
               const config = await getApiConfig()
               if (config) {
                 await createApi(config).deleteMeasurement(m.id)
                 await removeMeasurement(m.id)
               }
-            } catch {}
+            } catch {
+              await load()
+              return
+            }
             load()
           },
         },