QuantumLock cache boundary detection fails with multi-turn system prompts #17
Description
Using claw-compactor with a multi-turn conversation where the system prompt spans multiple messages. QuantumLock correctly identifies the cache boundary on the first call, but on subsequent calls with the same system prompt, it doesn't recognize the prefix overlap.
This means we're missing the Anthropic prompt caching discount on repeated calls.
Is QuantumLock expected to handle cross-call prefix detection, or is that out of scope?