timeless_logs

# Changelog

This changelog starts at 1.5.5; earlier releases are recorded by git
tags and `bench/results/*.md` session documents.

## 1.7.0 (2026-08-09)

**Automatic legacy conversion.** Starting on `engine: :libsql` over an
unmigrated legacy block store now runs the journaled, resumable,
digest-verified `ReleaseStartup.prepare/2` conversion automatically at
startup (exclusive owner lock; source retained for rollback), instead
of refusing. Set `auto_migrate: false` to restore the strict refusal.
The legacy Elixir block engine is deprecated for removal in roughly
three months (~2026-11).

## 1.6.0 (2026-08-09)

**Opt-in libSQL storage engine** (`config :timeless_logs, engine: :libsql`)
— the port of the runtime to the timeless-libsql v0.5.0 logs virtual
table, replacing the deprecated Elixir block engine for hosts that opt
in. One `logs.db` holds everything; rich log messages get CLP codec-8
template compression at optimize; embedded and external (Rust
`timeless-logs-api`) modes share one on-disk format, so a host graduates
to the Rust owner by switching owners, not migrating data.

- Full facade coverage: ingest (rich-v1 batches), flush/optimize,
  query/count (ts+level pushdown + the shared Filter residuals — parity
  with the Elixir engine by construction), stream and the field
  aggregations, stats, VACUUM INTO backup, subscriptions.
- Startup refuses an unmigrated legacy block store loudly (run
  `TimelessLogs.ReleaseMigration` first); cold-reopen durability via a
  final flush on shutdown.
- Default engine remains `:elixir`, completely unchanged; the flip ships
  as its own release. No Elixir HTTP child under `:libsql` — HTTP serving
  belongs to the Rust services.
- Port plan: `notes/libsql_engine_port_plan_2026-08-09.md`.

## 1.5.5 (2026-08-08)

Validated against the released **timeless-libsql v0.5.0** and re-pinned
the CI/release workflows to that tag (they previously built a pre-0.4.0
development rev, 409 commits behind). The capability preflight —
data ABI 1 + rich-v1 logs batches — passes unchanged, and the full
suite (230 tests, including crash-boundary migration resume and
cold-parity validation over 8,193 entries) is green against v0.5.0.

- **Message compression:** the migration's final `optimize` under a
  v0.5.0 extension now template-compresses rich log message columns
  (CLP-style codec 8; timeless-libsql measured 1.29–2.44× smaller
  blocks on message-dominated corpora, with a per-block fallback that
  never regresses). Consequence: once a migrated `logs.db` has been
  optimized by v0.5.0, its readers need timeless-libsql ≥ 0.5.0 —
  pre-0.5.0 extensions refuse the new blocks loudly.
- The libSQL migration candidate now traps exits so its connection and
  WAL close even when the linked migration caller dies mid-run.