In shadow/dry-run/kill-switch modes, when the target has no token/recipient/
chat, or when not in the canary cohort, the handlers returned without marking
the notification, so the poller (pendingFilter on notified:{$ne:true})
re-selected the same batch every cycle forever (observed: fcm:500 every 10s).
Add a service-owned per-channel marker processedBy.<channel>, set in every
terminal 'won't/can't send' branch, and exclude marked docs in pendingFilter.
Unlike the shared notified/emailNotified/telegramNotified flags, processedBy is
invisible to the old system, so it never suppresses a real send in prod shadow.
- types.ts: NotificationDoc.processedBy?: Partial<Record<Channel, Date>>
- poller.ts: pendingFilter excludes processedBy.<channel>
- handlers.ts: markProcessed() in no-token/no-recipient/no-chat, decideSend=false,
dead-token and telegram-blocked branches
- fake-repo: dotted-path support in matching and $set/$unset
- tests: regression test + processedBy assertions (86 passing)
vjrj
6d1ba439a2