# Player progression has three scopes, not two

Progression state was two scopes — `PlayerState` (persisted) and `SessionState` (transient) — with achievements
and best times leaking out as special cases: `PlayerState.Reset()` deliberately skipped `UnlockedAchievements`,
and best times lived in the ghost replay files rather than the save. We split progression into **Attempt**,
**Playthrough** and **Profile** (defined in `CONTEXT.md`), because introducing save slots makes the third scope
mandatory rather than a preference: Steam achievements are per-account and cannot be un-earned, so a
per-Playthrough achievement list would permanently contradict Steam the moment a second slot exists. Best times
follow the same argument — a completionist's record is not something starting a new game should reset.

## Considered options

Keeping one persisted root with a hand-maintained list of fields that survive New Game. Rejected: that is exactly
what the old `Reset()` did, and it had already drifted — achievements survived by omission rather than by design,
and nothing would have caught the next missed field.