Node.js 26 becomes LTS on 2026-10-28: support dates and what breaks from Node 24

Node.js 26 is Active LTS from 2026-10-28 to 2027-10-20 (EOL 2029-04-30). Node 24 is in maintenance since 2026-10-20 (EOL 2028-04-30), Node 22 EOL 2027-04-30, Node 20 EOL since 2026-04-30. Node 26 removes `res.writeHeader()`, the `_stream_*` modules and `--experimental-transform-types`, deprecates `module.register()`, and enables Temporal. From Node 27 every line becomes LTS (alpha in October, Current in April, LTS the next October).