Stream Aggregation Helper

Design, deploy, and verify stream aggregation rules for VictoriaMetrics. Stream aggregation reduces cardinality, sample frequency, or query cost by aggregating samples by time and by labels at vmagent (or single-node vmsingle) before they reach storage.

The skill walks through five phases:

1. Gate — is stream aggregation the right tool for this problem?
2. Intake — current cardinality, collection topology, what consumers need.
3. Decide — where in the pipeline, interval, output function, by/without, scaling.
4. Config — produce a ready-to-apply YAML plus a phased rollout plan.
5. Verify — queries and vm_streamaggr_* metrics that confirm the rule is doing what was intended.

Environment

Uses the same env vars as the victoriametrics-query skill. The skill works without these (interview-only mode) but is much more accurate when it can query the user's VictoriaMetrics directly.