fix: update sync plugin to work with the latest Electric sync server

[samwillis]

This fix is something of a stop gap untill we make some larger changes to the plugin and bring in multi table/shape sync.

[github-actions]

Built bundles:

• Postgres WASM: https://github.com/electric-sql/pglite/actions/runs/13284245463/artifacts/2577986514
• Interim build files: https://github.com/electric-sql/pglite/actions/runs/13284245463/artifacts/2577986643
• PGlite: https://github.com/electric-sql/pglite/actions/runs/13284245463/artifacts/2578020348
• Demos: https://github.com/electric-sql/pglite/actions/runs/13284245463/artifacts/2578043684
• Demos: https://github.com/electric-sql/pglite/actions/runs/13284245463/artifacts/2578800571

[copiltembel]

@samwillis I've pushed a stylecheck fix but some tests are failing on CI due to offset property missing in Message.

Error: packages/pglite-sync typecheck: test/sync.test.ts(558,7): error TS2353: Object literal may only specify known properties, and 'offset' does not exist in type 'Message'.

[samwillis]

@copiltembel 🤦‍♂️ I had forgotten to run pnpm typecheck before pushing. Fixed now, just removed the offending props.

Ready for a final review.

[copiltembel]

LGTM!

[github-actions]

🚀 Deployed on https://67aca74792cc8f65232b2e10--pglite.netlify.app