The read model lives in memory

• Context: deriving rows per request costs a query per row on every refresh.
• Decision: writes note an in-memory change log; the read model rebuilds rows from one store snapshot on change and serves deltas that clients pull after an event.
• Consequence: serving rows costs no SQL; a restart starts a new epoch and clients reload.
• Enforced by: TestEveryWriteNotes, TestEveryExportedMethodIsReadOrNoted, the projection tests.