feat: optimize routes around accommodation, confirm note deletions (#1123)

Optimize day routes around the accommodation

When a day has an accommodation set, the route optimizer now treats it as
the day's home base: it optimizes a loop that leaves the hotel and returns
to it, so the stop nearest the hotel comes first. On a transfer day -
checking out of one hotel and into another - the route runs from the first
hotel to the second instead.

The optimizer also gained a 2-opt pass on top of the nearest-neighbor
ordering, which removes the crossings the greedy pass used to leave behind.
A new display setting ("optimize route from accommodation", on by default)
lets you turn the anchoring off.

Confirm before deleting notes

Deleting a plan note or a collab note now asks for confirmation first. On
phones and tablets the edit and delete icons sit close together and were
easy to mis-tap, which deleted notes with no way back.

client/src/store/settingsStore.ts

@@ -32,6 +32,7 @@ export const useSettingsStore = create<SettingsState>((set, get) => ({
     temperature_unit: 'fahrenheit',
     time_format: '12h',
     show_place_description: false,
+    optimize_from_accommodation: true,
     map_provider: 'leaflet',
     mapbox_access_token: '',
     mapbox_style: 'mapbox://styles/mapbox/standard',