- Pool the `[]driver.Value` slice passed to scalar/aggregate UDF callbacks and to vtab `Filter`/`Insert`/`Update` callbacks, eliminating the dominant per-row allocation on UDF-heavy queries. Benchmarks on a 1000-row, 3-arg noop scalar UDF show ~40% fewer bytes/op and ~15% fewer allocs/op.
- Document the matching "arguments are not valid past return" contract on `vtab.Cursor.Filter` and `vtab.Updater.Insert`/`Update`, consistent with the existing rule for `FunctionImpl.Scalar` / `AggregateFunction.Step` / `WindowInverse`.
- Resolves [GitLab issue #226](https://gitlab.com/cznic/sqlite/-/issues/226). See [GitLab merge request #114](https://gitlab.com/cznic/sqlite/-/merge_requests/114), thanks Ian Chechin!