v5.3.0-beta.0

What's Changed

• fix(ci): pin actions/setup-node version comment to v6.3.0 by @wochinge in https://github.com/langfuse/langfuse-js/pull/792
• chore(ci): pin remaining action version comments to immutable patch tags by @wochinge in https://github.com/langfuse/langfuse-js/pull/793
• chore: improve codex agent setup by @hassiebp in https://github.com/langfuse/langfuse-js/pull/797
• feat(client): add experiment runner context by @wochinge in https://github.com/langfuse/langfuse-js/pull/795

Full Changelog: https://github.com/langfuse/langfuse-js/compare/v5.2.0...v5.3.0-beta.0