observability: backend-agnostic error-capture seam (Phase 1, inert until SENTRY_DSN)

.env.example

@@ -50,6 +50,13 @@ EMAIL_FROM=
 # openssl rand -hex 32
 CRON_SECRET=
 
+# Error monitoring (optional). Sentry-format DSN for a self-hosted GlitchTip
+# (or any Sentry-compatible) ingest endpoint. Unset = the capture seam no-ops
+# (no events sent), so the app ships dark until the backend is provisioned.
+# Server-side capture only (money path, crons, server actions); no client SDK.
+# Example: https://<publicKey>@glitchtip.hackerspace.sh/1
+SENTRY_DSN=
+
 # Docker build flag (only when building the standalone image)
 # Set to "1" in the Dockerfile so next.config.mjs emits standalone output.
 # DOCKER_BUILD=1