[lakhansamani]

Cuts the [Unreleased] section to 2.4.3. Changelog header only — no code.

Contents of 2.4.3:

• fix(storage): make the cassandradb provider correct on apache cassandra and scylla #824 — cassandradb provider correctness on Apache Cassandra (LIKE rejection, unanchored session-token delete on five backends, single-use token double-claim)
• fix(storage): stop mixing LWT and plain writes on cassandra partitions #818 — the LWT/plain timestamp-domain fix, with its Apache Cassandra "truncation margin" mechanism retracted as measured false
• docs(changelog): record the cassandra LWT delete-drop fix #820 — changelog for fix(storage): stop mixing LWT and plain writes on cassandra partitions #818
• docs: add Pethost to the one-click deployment options #817 — Pethost one-click deployment entry

All fixes and docs. No schema or data migration, no breaking change.