Chat history implementations.

1. conversation storage
2. understand prompt instructions with contextual memory
3. recognize references to previous prompting responses
4. identify when changes in conversation state effect previous decisions
5. resolve conflicting morals or tone in past decisions

No files, tests, or entry points are named. Start by locating the existing conversation and prompt-handling code, then clarify how storage, contextual memory, references, state changes, and conflicting prior decisions should work; done requires agreed behavior and coverage for all five areas.

索引モデルが issue の本文から書いたものです。