Resolve CDS version-file conflicts

CDS ships many packages, and the cds release group (web, mobile, common, mcp-server) is version-locked. When both master and the current branch bump package versions independently, a rebase (or merge) collides on two file types only:

• packages/<pkg>/package.json — the "version" field
• packages/<pkg>/CHANGELOG.md — the top-of-file version entries

This skill resolves only those two file types mechanically. Anything else that conflicts must be raised to the user.

Prefer re-running the release when the plan is recoverable. Versions and changelog entries are generated by nx release from the version plans in .nx/version-plans/. If you still have the branch's plan file (or can recreate it with yarn nx release plan), the cleanest fix is to take master's side of both conflicted files, restore the plan, and re-run yarn release. Use the manual recomputation below only when that is not practical. See docs/release.md.