Memory backends

Carina supports pluggable episodic memory stores.

Backend	When to use
builtin (default)	Postgres + pgvector, or SQLite in local mode
honcho	Honcho cloud memory
mem0	Mem0 cloud or self-hosted

carina memory backends
carina memory use builtin
carina memory test

Set CARINA_MEMORY_BACKEND in ~/.carina/.env. RAG vectors still use Postgres when available.

Developer details: Memory architecture.