Agent Skills: dependency-updater

Runs dependency updates end to end: parallel per-package research scaled to semver, applies the whole set at once, then fixes what the quality gate actually reports. Files a Linear issue to track the run, then asks up front whether to work in an isolated worktree and whether to finish by merge or PR, shipping through /finish and removing its own worktree when done. Invoked when users request package updates, dependency updates, version bumps, or mention 'ncu' or npm-check-updates.