Upgrade the JS/TS SDK safely

Before upgrading, read CHANGELOG.md and BREAKING_CHANGES.md, test against the target Conductor server, and pin the new package version in a staging environment. Run unit tests and one representative workflow and agent execution before production rollout.

Configuration env vars are CONDUCTOR_*/CONDUCTOR_AGENT_*-prefixed with no legacy alias — this is a clean break, not a compatibility shim, so renaming an old env var name is required, not optional, when upgrading across a major that changed it (see CHANGELOG.md's [Unreleased] entries for the current set). Roll back by restoring the prior package lock and keeping workflow definitions versioned rather than changing active behavior in place.