pub fn classify(
prev: Option<(u64, u64)>,
curr_hash: u64,
now: u64,
ttl_secs: u64,
) -> CacheOutcomeExpand description
Pure classification of a turn’s cache outcome. prev is the conversation’s
previous (prefix_hash, last_touch), curr_hash this turn’s cacheable-prefix
hash, now/ttl_secs the idle clock. Pure (no globals, no I/O) so the
TTL-vs-prefix decision is unit-tested independently of the live store.