chore: bump Node.js minimum to 20.19+ for vite 8 dev testing #76

Context

Vite 8 depends on rolldown, which requires Node.js ^20.19.0 || >=22.12.0 (uses node:util.styleText added in 20.12.0). The current .nvmrc pins Node.js to 20.5.1, which prevents using vite 8 as a dev dependency alongside vitest 4.1+.

Currently:

• Peer dep: vite ^4.2.0 || ^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0 (added in feat(vitest-plugin): add vite 8 support #74)
• Dev dep: vite ^7.0.0 (reverted in fix(vitest-plugin): stop importing the deprecated vitest subpaths #75 to keep tests running on Node 20.5.1)

What needs to happen

1. Bump .nvmrc to 20.19.0 (or higher)
2. Update CI matrix Node versions accordingly
3. Restore vite dev dependency to ^8.0.0
4. Re-add rolldown dev dep and tsconfig.json paths for vite 8 type resolution

Existing PRs that would unblock this

• chore: bump node, pnpm and rollup #40 — chore: bump node, pnpm and rollup (adds Node 22.12.0 to CI matrix)
• Upgrade node to 24 #53 — Upgrade node to 24 (bumps .nvmrc to 24.4.1, CI matrix to [20, 22, 24])

Either of these PRs landing would satisfy the Node.js requirement for vite 8 + rolldown. After one merges, the vite dev dep can be restored to ^8.0.0.

Related

• feat(vitest-plugin): add vite 8 support #74 — feat(vitest-plugin): add vite 8 support
• fix(vitest-plugin): stop importing the deprecated vitest subpaths #75 — fix(vitest-plugin): migrate deprecated vitest 4.1 imports