v0.19.0

A cloud's own alarms: replayed where they are written in PromQL, on every
cloud that has such alarms, and judged from their history where they aren't.

• CloudWatch PromQL alarms. --rules reads the AWS CLI's
  describe-alarms answer: a PromQL alarm is replayed with its pending
  period as for, its recovery period as keep_firing_for and its
  evaluation interval; metric and composite alarms are listed as not
  replayed. --prometheus https://monitoring.REGION.amazonaws.com --auth aws
  queries CloudWatch's PromQL API, signed for the service monitoring, as
  is its dual-stack (REGION.api.aws) or VPC endpoint name; aps stays for
  Amazon Managed Service for Prometheus. A period given as NaN is refused.
• Google Cloud alerting policies with a PromQL condition. --rules
  reads them as gcloud monitoring policies list writes them, in YAML or
  JSON, or as the API's list answers: the condition's duration is for,
  its evaluation interval (30 s when it doesn't say) the rule's, its
  alertRule and ruleGroup the name and group (the policy's display name
  otherwise), its labels the rule's, and the policy's severity becomes
  severity. An alert closes at the first evaluation at least the larger of
  270 s and two evaluations after its condition last held, as Google Cloud
  closes them. A disabled policy, and one with another kind of condition, is
  listed as not replayed. Replay with --gcp-project, whose PromQL API
  answers for the same metrics, and --step 30s, of which every policy's
  interval is a multiple.
• An answer cut short is an error. An API that caps the series in an
  answer and says so only in a warning (CloudWatch: 500) no longer gives a
  replay of what was left: the rule's query fails, saying why.
• Firings from a cloud's alarm history. recipes/firings has a script
  for each cloud that writes its alarms' history as --firings takes it:
  cloudwatch.sh (describe-alarm-history), azure-monitor.sh (Azure
  Resource Graph), google-cloud.sh (projects.alerts.list) and oci.sh
  (get-alarm-history), each with the cloud's own CLI, tested against the
  clouds' documented answers with stand-ins for the CLIs. Times are checked
  to be times before they reach a query or a filter (UTC for Azure), the
  token goes only to https, a CloudWatch move that says neither its old nor
  its new state stops the script, and a stateless Azure alert (activity log,
  service and resource health) ends as it fires.