refactor(session): replace MigrationEngine and isolate migrate command - #1195

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/github-script@v7. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

code-erosion: could not post the PR comment (Resource not accessible by integration). See the job summary.

No file matched to [/home/runner/work/teamai-cli/teamai-cli/**/*requirements*.txt,/home/runner/work/teamai-cli/teamai-cli/**/*requirements*.in,/home/runner/work/teamai-cli/teamai-cli/**/*constraints*.txt,/home/runner/work/teamai-cli/teamai-cli/**/*constraints*.in,/home/runner/work/teamai-cli/teamai-cli/**/pyproject.toml,/home/runner/work/teamai-cli/teamai-cli/**/uv.lock,/home/runner/work/teamai-cli/teamai-cli/**/*.py.lock]. The cache will never get invalidated. Make sure you have checked out the target repository and configured the cache-dependency-glob input correctly.