## Added

- Emit distribution metrics from the Ecto integration.

  Each Ecto query telemetry event now also reports its timing values as `ecto_query_time`, `ecto_queue_time`, `ecto_decode_time`, `ecto_idle_time` and `ecto_total_time` distribution metrics.

  All five metrics are tagged by `repo` and `hostname`. The `ecto_query_time`, `ecto_decode_time` and `ecto_total_time` metrics are additionally tagged by `repo` and `source` (the Ecto table).

  This surfaces pool waits, decode time, idle connection time and per-table latency as standalone metrics in addition to the existing query span.

## Fixed

- Preserve sub-millisecond precision when reporting timing distribution metrics.

  The Ecto (`ecto_query_time`, `ecto_queue_time`, `ecto_decode_time`, `ecto_idle_time`, `ecto_total_time`) and Oban (`oban_job_duration`, `oban_job_queue_time`) distribution metrics now report fractional milliseconds, instead of being truncated to whole milliseconds. Sub-millisecond measurements were previously rounded down to zero.