Operation timing events and opt-in native storage metrics.

Public database operations, direct query execution and individual query stream open/next/close calls emit [:lancedb, :operation, :start | :stop | :exception]. Metadata includes :operation, :operation_id, and :execution_id. A query enumeration shares its execution ID across open/next/close events; eager queries also provide :parent_operation_id on child events. Independent callback operations receive independent IDs; stop metadata includes :status (:ok or :error) and :error_kind. Direct query execution also identifies :query_kind. Public calls made inside callbacks emit their own spans. Internal adapter calls do not emit spans. Durations use Erlang native time units. Records, SQL, connection credentials, and table handles are not included. Exception events use the standard telemetry exception metadata, which can contain user data in the exception reason or stacktrace.

Call enable_native_metrics/0 before opening connections to collect native metrics. The recorder is process-global, cannot be disabled, and reports cumulative values across all connections in this NIF. It does not reset when read. An incompatible existing native recorder produces an error.

For session-local index and metadata cache statistics, use LanceDB.Table.cache_stats/1; that API needs no global recorder and reports the table's actual session, including any other handles sharing its caches.

poll/0 emits one [:lancedb, :native, :metric] event per metric series. Scalar measurements contain :value; histogram measurements contain :count and :sum. Metadata contains :name, :kind, :attributes, and histogram :buckets (cumulative pairs of upper-bound strings and counts).

These are cumulative snapshots, not individual observations: do not sum successive counter snapshots or feed histogram sums into a distribution. Metric names and attributes stay strings and depend on the upstream SDK. Native attributes may include storage paths; filter them before export when necessary. Call poll/0 from your own scheduler or telemetry_poller; this package starts no background polling process.