* feat: expose BlockKeyCacheSize and enable WriteThrough when bloom filter disabled
* import/config: add BatchMaxSize and BatchMaxNodes
* config: make BlockKeyCacheSize an OptionalInteger
* config: add and wire datastore.WriteThrough option
* config: omitempty on BlockKeyCacheSize
* changelog: rewrite entry about new options for the datastore
* config: add docs for BatchMaxNodes and BatchMaxSize
* config: make WriteThrough an optional Flag
* changelog: improve description of new datastore/import options
* refactor: DefaultWriteThrough as bool
* chore: boxo v0.26.0
* docs: config and changelog fixes