Pick a replacement messaging service for ntfy

[koinsaari]

Summary

ntfy was removed during the repo restructure for a clean slate. A replacement push/notification service is wanted but not yet chosen.

Context

ntfy lived on the edge VPS and served push notifications for arr-stack / system events from the home box. It was removed (data dirs deleted, Caddy block removed) when reorganizing into Stoganet/edge. The use case stands; the implementation is open.

Scope

• Decide what role the service plays: webhook receiver only, or full mobile-push (FCM/APNs)?
• Pick a tool: ntfy again, Gotify, Apprise, Matrix, Discord webhook, something else
• Decide where it runs: edge VPS (public), home box (NetBird-only), or external

Acceptance criteria

• Service picked and rationale captured
• If self-hosted, deploy lives in the appropriate repo (edge for public, infra for home)
• Existing producers (whatever was pushing to ntfy) point at the new endpoint

Notes

Draft / future work. No urgency. Filing so the reasoning from removing ntfy isn't lost: it was a "clean slate before reorg" decision, not a "ntfy is bad" decision — coming back to ntfy is fine.