Release v0.2.4

[pinodeca]

Tracking issue for the v0.2.4 release. Procedure: prompts/pg_durable-release.md.

Cut line (PRs in this release): everything merged to main through ae300be (#283), plus the changelog-curation PR #287.
Release strategy: cut v0.2.4-rc1 first (pre-release, soak), then final v0.2.4.
Tag commit: 05cd2b68f869f1d98bf1b8de7c84664d2e2dface (#287 merge — contains the dated changelog).
Published by: Pino de Candia (@pinodeca).

Gates

• Cut line confirmed (v0.2.3..main; tip ae300be / Reconcile df control-plane with the durable engine #283)
• Changelog curated & dated — full [0.2.4] section from all PRs since v0.2.3, merged to main (PR docs(changelog): curate and date the v0.2.4 release section #287)
• Version/upgrade-script sanity (Cargo.toml=0.2.4, pg_durable.control @CARGO_VERSION@, sql/pg_durable--0.2.3--0.2.4.sql)
• Tag commit recorded (= docs(changelog): curate and date the v0.2.4 release section #287 merge commit 05cd2b6)
• CI green on tag commit (run 28620989990: clippy, unit, E2E, upgrade tests, pg_regress on PG17 + PG18)

Release candidate

• Tagged v0.2.4-rc1 -> draft Release (run 28622546251; PG17/18 .deb + source + SHA256SUMS attached)
• Published as pre-release (approved by: @pinodeca / Pino de Candia)
• GHCR immutable RC images confirmed (run 28626609331; PG17+PG18 logs: "immutable tags only", no floating tags moved) — 0.2.4-rc1-pg17/18, v0.2.4-rc1-pg17/18
• RC soak sign-off

Final

• Tagged v0.2.4 -> draft Release (run #…, release: …)
• Release published (approved by: …)
• GHCR images confirmed — immutable 0.2.4-pg17/18 + floating pg17/pg18/latest (run #…)
• Next-cycle PR opened (#…)

Note: apply the same Contributors section to the final v0.2.4 notes (see #286 discussion).