Node: Support using node:sqlite and encryption

[simolus3]

This PR updates the node driver to use the the powersync_update_hooks helper instead of registering update hooks on the SQLite connection.

Because update hooks were the only reason we needed a better-sqlite3 fork, this migrates the package back to upstream better-sqlite3 (which is nice because that has prebuilts set up and is much easier to install).
Additionally, this allows customizing workers to load another package instead of better-sqlite3. This is particularly interesting for e.g. better-sqlite3-multiple-ciphers for encryption. I've updated the node demo to support both packages, switching between them depending on environment variables.

Because update hooks are no longer something we need from the underlying driver, this also adds an experimental database implementation based on node:sqlite APIs.
I've made better-sqlite3 an optional peer dependency, and I'm only importing it conditionally when it's actually used. This works well with the node demo, but for apps that use bundlers, the bundler needs a static hint to bundle better-sqlite3 now. I've adopted the Electron demo, and added a section about this to the readme.

[changeset-bot]

🦋 Changeset detected

Latest commit: 8ef7933

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@powersync/node	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[rkistner]

This looks quite promising!

If this works well, we could perhaps switch to node:sqlite by default when we do a v1.0 release, moving better-sqlite3 support to a separate package or import (removing it from the default dependencies).

I'm also wondering: Could we use the same approach for update notifications for better-sqlite3? Would that allow us to switch back to upstream better-sqlite3, or are there other blockers currently?

[simolus3]

Could we use the same approach for update notifications for better-sqlite3

Yes! I've refactored the connection setup to share that between node:sqlite and better-sqlite3.

Would that allow us to switch back to upstream better-sqlite3, or are there other blockers currently?

That seems to have been the only blocker, I've migrated the package back to better-sqlite3.

I've also expanded the worker API to allow custom better-sqlite3 forks, the demo now supports encryption thanks to this.

we could perhaps switch to node:sqlite by default when we do a v1.0 release

To prepare for that, I've made better-sqlite3 an optional peer dependency. That is a breaking change, because:

• users now need to import that package.
• we only import better-sqlite3 with a dynamic import() / require() call when it's actually used (to avoid having it as a dependency when users want to use node:sqlite). This breaks some bundler setups, but I've described the issue in the readme and updated the examples.

Still, I think it's worth it because we need this for encryption / to later support node:sqlite.