Release v3.1.2

Concord 3.1.2 repairs VSR log validation, backup checksum portability, read deadlines, and bounded key-range pages.

• Fix #94: committed-prefix checks walk retained entries once and skip compacted operation numbers while retaining corruption checks.
• Fix #95: new backups use versioned deterministic ETF checksums and verify across independent VMs on the same OTP major release.
• Fix #96: primary discovery, quorum-confirmed reads, and redirects share one timeout budget. Unavailable discovery returns a structured error.
• Fix #97: Concord.KV.list/1 prefix/range pages seek maintained ordered indexes in the Local and VSR engines. Ordering, revision reads, expiry, tombstones, and existing snapshot formats are preserved.

Legacy backup checksum mismatches remain invalid, and unknown schemes are rejected. Recreate affected legacy backups on their originating VM after upgrading. OTP does not guarantee identical deterministic encoding across major releases; validate restore before changing OTP major versions.

Paging skips unrelated keys. Expired or deleted candidates inside the selected range still require inspection. Legacy prefix_scan and the compatibility state-machine adapter retain their existing full-inventory costs.

All three packages are published at 3.1.2:

• concord
• viewstamped_replication
• ex_turso

{:concord, "3.1.2"}

Concord requires the matching companion versions. ExTurso builds its included native source and continues to use Turso 0.8.2.