Tag every memory write with identity scopes and compose them at retrieval time

Mem0·medium signal

Multi-scope memory tags each write with identity scopes (user_id, agent_id, session_id) so that at retrieval time you compose the relevant scopes and let results merge and rank automatically. This avoids leaking one user's or session's context into another and lets a single memory layer serve per-user, per-agent, and shared-team knowledge without separate stores.