[DIFF] Time-travel queries — query data as of any point in time

[ElioNeto]

Differentiator

Git-like versioning for key-value data. Query, diff, and restore data from any timestamp without manual snapshots.

Description

engine.get_as_of("invoice:42", yesterday_ts)
let history = engine.history("invoice:42")
let diff = engine.diff("invoice:42", ts_a, ts_b)

Implementation

Store all value versions in a version chain. Compaction merges old versions based on configurable retention.

Impact

• Audit logging without separate infrastructure
• Undo for applications
• GDPR right-to-explanation

[ElioNeto]

Implemented in commit 0871d91.