Update watcher runtime to Node 22

[phroi]

Why

• Align watcher with the Rosen Node 22 runtime baseline.
• Keep release packaging and GitHub release workflow on the same Node version.
• Fix Node 22 bundling resolution issues found during build verification.

Changes

• Update Node references to 22.18.0 in .nvmrc, Dockerfile, package engines, lockfile, and release workflow.
• Update @types/node to the Node 22 line.
• Adjust Rollup CommonJS and node-resolve settings for Node 22 packaging.
• Add a changeset for the runtime bump.

Dependency Notes

This is the watcher-side Node 22 migration. It should land after the package-level ESM fixes are published from:

• Fix notification ESM imports notification#1
• Fix extended-typeorm ESM imports utils#6

After those packages are released, watcher should be re-verified against the published versions before the final watcher release.

Checks

• npx npm@11.6.2 run type-check
• npx npm@11.6.2 run build
• npx npm@11.6.2 run test: 181 passing

[phroi]

BTW watcher still has the old JSON imports using assert { type: 'json' }.

Conversely, Node 22 prefers the newer import attributes syntax (with { type: 'json' }), but watcher is still on TypeScript 4.x (typescript@^4.7.2), so I would likely need to bump the Typescript version too.

If you want, I can modernize those JSON imports in this PR, but I expect that to fit better in a separate TypeScript/tooling update so the syntax change and parser support can be verified together.

Phroi