Persist project decisions in reviewable `.agent-memory/` markdown. Use when asked to "remember a project decision", "save session learnings", "initialize .agent-memory", "manage project memory", "migrate memory", "build memory from docs", "sync memory", "run memory maintenance", "check memory status", or "onboard a new developer"; when `.agent-memory/` or `AGENTS.md` memory pointers are in play; when sharing project context, conventions, or session handoffs with another developer or reviewing project memory in a pull request; or when context "forgets between sessions". Sync reconciles files already in the checkout. Not for vendor auto-memory consolidation, personal agent rulebooks, memory leaks, RAM usage, or human memory.