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.

shared/src/i18n/zh/collab.ts

@@ -39,6 +39,8 @@ const collab: TranslationStrings = {
   'collab.notes.cancel': '取消',
   'collab.notes.edit': '编辑',
   'collab.notes.delete': '删除',
+  'collab.notes.confirmDeleteTitle': '删除备注？',
+  'collab.notes.confirmDeleteBody': '此备注将被永久删除。',
   'collab.notes.pin': '置顶',
   'collab.notes.unpin': '取消置顶',
   'collab.notes.daysAgo': '{n} 天前',