Release v3.1.3

Concord 3.1.3 records the resolution of #98 and publishes the matching package family.

The quadratic committed-prefix validation reported against 3.0.6 was repaired in 3.1.2. Growing retained-log benchmarks confirm linear validation work, and the existing corruption, compaction, and committed-entry safety tests pass. Complete transition validation remains O(retained entries).

Applications pinned to 3.0.6 can adopt the published fix with:

{:concord, "3.1.3"}

Concord requires matching 3.1.3 versions of both companion packages:

• concord
• viewstamped_replication
• ex_turso

ExTurso builds its included native source and uses Turso 0.8.2.