Rule ID: MET-004
Description: Histogram metrics consistently use the same histogram buckets per metric name.
Rationale: Histograms use buckets to count occurrences in given ranges. Inconsistent buckets may make quantile aggregations less precise.
Target: Metric
Criteria: Given a metric name, all time series of type histogram with that metric name in the past 14 days MUST have the same histogram buckets.
Impact: Normal