Initial commit: notifications, monitoring, on-call and incidents

One binary and one SQLite file. Topics with ntfy-style publish and
subscribe, HTTP/TCP/DNS/TLS/heartbeat monitors with a public status page,
schedules and escalation policies, and incidents with a timeline and
post-mortem. The UI follows the Lightwell design language.

Builds against an unreleased Reef (secretbox) through a local replace line.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,7 @@
+.env
+*.db
+*.db-wal
+*.db-shm
+master.key
+.devdata/
+bin/