ragleap-observability v0.4.0

Added

• Optional Slack and email AlertManager receivers (alertmanager.receivers.*), disabled by default. Credentials come from a user-created Secret via api_url_file / smtp_auth_password_file, never from values.
• required guards for the email fields.

Verified

• helm template (4 scenarios) and amtool check-config on prom/alertmanager:v0.27.0.
• Live on a kind cluster against a Slack-compatible stand-in: Secret mounts read-only, PostgresExporterDown fired after exactly 5 minutes, FIRING and RESOLVED were both delivered.

Known limitations

• No real Slack or email send has been confirmed yet.
• PagerDuty is not supported.
• AlertManager state is still on emptyDir.