chore: release v1.25.0-beta.1

[hongzexin]

Summary

• Prepares beta release v1.25.0-beta.1 for the 1.25.0 stable train.
• Updates release-managed version files only; release-please remains the stable release owner.
• Merging this PR will publish v1.25.0-beta.1 only after the release-candidate validation checklist below is completed for this exact candidate SHA.
• Synced automatically from release-please PR chore(main): release 1.25.0 #46; no manual beta workflow dispatch is required.

Changes since the previous release

Initial beta prerelease for this stable train.

Release-candidate validation

Validated candidate: 1349170

Complete these checks on the exact candidate SHA above before merging. The beta release guard and publish workflow fail while any item remains unchecked or the SHA is stale.

• Backend/unit/integration gates
• Frontend tests/build
• Wheel/package validation
• Docker/container smoke
• Live upstream/account smoke
• Live upstream/account smoke not required

Install after publish

uvx --from "codex-lb==1.25.0b1" codex-lb
docker pull ghcr.io/chekdata/codex-lb:1.25.0-beta.1
helm install codex-lb oci://ghcr.io/chekdata/charts/codex-lb --version 1.25.0-beta.1 --devel

Promotion

Merge the normal release-please PR to promote this beta-tested train to 1.25.0.