Per-identity cursor store the watcher uses to ask each source only for invites new since last
sweep. Pluggable so a host can persist cursors (survive restarts) — the default is an in-memory
map, which is correct for a single long-lived process and harmless (re-scan + dedupe) across
restarts.
Per-identity cursor store the watcher uses to ask each source only for invites new since last sweep. Pluggable so a host can persist cursors (survive restarts) — the default is an in-memory map, which is correct for a single long-lived process and harmless (re-scan + dedupe) across restarts.