Reap orphaned frontend HTTPS probe processes (#57)

docs/local-development.md

@@ -27,6 +27,13 @@ project directory. Dockerfiles are in `infra/images/`. Runtime and startup files
 are grouped by service under `infra/local/`. The stack consists of Vault, Mongo,
 NATS, notifications, BFF and Caddy serving the frontend.
 
+The frontend container uses Compose `init: true` to reap orphaned `ssl_client`
+children created by BusyBox's HTTPS `wget` health probe. Keep this enabled:
+Caddy alone does not reap those children when it runs as PID 1, and repeated
+probes can accumulate thousands of zombie processes. Recreate the frontend
+container when applying this setting; restarting an old container does not
+change its init configuration.
+
 On first startup, bootstrap initializes/unseals persistent Vault, provisions
 AppRoles and secrets, initializes Mongo replica set `rs0`, configures Vault's Mongo
 plugin, and starts authenticated NATS JetStream. Product startup fails explicitly