burn: reading a repository whole counts nothing older than --burn-days, yet marks the account counted #114

What happens. The burn store refuses any window dated before its fold point, which every open sets to now minus --burn-days (35 on vibescrobble.com). The fill pass reads a newly held account's repository back to the start of last year and puts every record into burn. Everything older than 35 days is dropped rather than folded into the dailies, and the account is then marked filled, so it is never read again.

How to reproduce. Store::open calls compact(now_utc()) (burn.rs:768, 803-808), and retire sets folded to that cutoff (burn.rs:623-624). Inner::put returns None for any window before folded (burn.rs:535-538). fill.rs:166-170 puts every record, then fill.rs:106-107 calls burn.mark_filled. A local test opened a store, put one line from 2 days ago and one from 60 days ago, and burn::summary(..)["own"]["all"]["scrobbles"] came back as 1.

Why it matters. docs/state.md says a lost burn.json "is rebuilt from the repositories" and that dailies are kept forever. In practice a lost or reset store, an account newly bot-labelled with months of history, or one taken off the denylist only ever gets its last 35 days, and its all-time totals and leaderboard rank stay short for good.