timeless_traces

# Changelog

This changelog starts at 1.4.5; earlier releases are recorded by git
tags and `bench/results/*.md` session documents.

## 1.6.0 (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).

## 1.5.0 (2026-08-09)

**Opt-in libSQL storage engine** (`config :timeless_traces, engine:
:libsql`) — the port of the runtime to the timeless-libsql v0.5.0
traces virtual table, replacing the deprecated Elixir block engine for
hosts that opt in. One `traces.db` holds everything; embedded and
external (Rust `timeless-traces-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-span-v1 batches, OTel exporter and
  HTTP OTLP routed through the engine seam), flush/optimize,
  query (service/kind/status/trace_id/time/duration pushdown + the
  shared Filter residuals — parity by construction), trace lookup by
  raw or hex id, service/operation discovery, stats, VACUUM INTO
  backup, subscriptions.
- Startup refuses an unmigrated legacy block store loudly (run
  `TimelessTraces.ReleaseMigration` first); cold-reopen durability via
  a final flush on shutdown.
- Default engine remains `:elixir`, completely unchanged; the flip
  ships as its own release. Rich-span-v2 fields stay out per the
  fidelity contract.
- Port doc: `docs/2026-08-09_libsql_engine_port.md`.

## 1.4.5 (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, 408 commits behind). The capability preflight —
data ABI 1 + rich-span-v1 batches — passes unchanged, and the full
suite (201 tests, including the 8,192-span checkpoint crash-boundary
migration walk and cold-parity validation) is green against v0.5.0.

- The libSQL migration candidate now traps exits so its connection and
  WAL close even when the linked migration caller dies mid-run.
- Note for migrated `traces.db` files: the migration's final `optimize`
  under a v0.5.0 extension writes current-generation blocks; readers of
  that database need timeless-libsql ≥ 0.4.0 (the capability handshake
  line), as before. Span batches remain rich-span-v1, which v0.5.0
  continues to accept; rich-span-v2 fields (links, trace_state, flags,
  schema URLs, dropped counts) stay explicitly unsupported per the
  fidelity contract.