Reload Policy tells the system when to call timeline() again
once it has run through all the entries you gave it.

The 3 Policies

.never       → never call timeline() again automatically
.atEnd       → call timeline() again after last entry passes
.after(date) → call timeline() again at a specific date

.never

return Timeline(entries: [entry], policy: .never)

System will NOT call timeline() again on its own.
Widget stays frozen on the last entry until something
explicitly tells it to refresh.

When to use:

User has pinned a specific state via Intent Configuration
→ no point reloading, nothing will change unless user edits widget

How to manually trigger a reload from the main app:

WidgetCenter.shared.reloadAllTimelines()

Call this from your main app whenever data changes
→ forces the system to call timeline() again

.atEnd

return Timeline(entries: entries, policy: .atEnd)

System calls timeline() again after the last entry's date passes.
Used when you have a fixed schedule that needs to repeat.

From the project's original version:

// 5 entries, one per hour
return Timeline(entries: entries, policy: .atEnd)

Entry 0 → 1:00 PM
Entry 1 → 2:00 PM
Entry 2 → 3:00 PM
Entry 3 → 4:00 PM
Entry 4 → 5:00 PM  ← last entry
         ↓
policy kicks in → system calls timeline() again
→ builds 5 fresh entries starting from 5:00 PM

.after(date)

let refreshDate = Calendar.current.date(byAdding: .hour, value: 1, to: Date())!
return Timeline(entries: entries, policy: .after(refreshDate))

System calls timeline() again at exactly the date you specify.
Used when you know precisely when new data will be available.