[Copilot]

Summary

Closes #1078.

• Require Node.js >=24.22.1 in all 22 public packages and align root, docs, benchmark, and .nvmrc requirements.
• Record Beachball major bumps for packages currently at 1.x or higher (including Lage v3 and Backfill v7), and minor bumps for 0.x packages including workspace-tools. Package versions and workspace dependency ranges will be updated by the normal release process.
• Remove disallowedChangeTypes from the Beachball config to permit these major releases.
• Test GitHub Actions on the exact minimum (24.22.1), latest 24.x, and 26.x across Linux, Windows, and macOS. Basic checks and docs workflows use the updated .nvmrc files. Pin the Azure release pipeline to 24.22.1.
• Add the Lage v3 migration requirement to the docs.

This draft intentionally does not upgrade dependencies, remove dependency pins, or update Node typings; those security upgrades will follow separately.

Validation

• Full yarn ci --concurrency 2 passed under Node.js 24.22.1: 121 tasks succeeded.
• Immutable Yarn install, Beachball change validation, touched-file formatting, and diff checks passed.
• Verified all public-package engine ranges and change types, minimum-version boundaries, CI runtime settings, and unchanged dependency declarations.