Add support for `wasm` with room

[BierDav]

Now that Room 3.0 with WASM Support is ready, it would be great if we could use powersync-kotlin accross mobile and web instead of having to map the whole api using @JsExport as we currently do 😊

https://android-developers.googleblog.com/2026/03/room-30-modernizing-room.html

[LouisCAD]

SqlDelight also supports WASM since this PR : sqldelight/sqldelight#5534 (i.e. since 2.1.0)

[simolus3]

A small update: #354 Allows compiling com.powersync:common for the web. That includes PowerSyncDatabase.opened, which allows using Room+PowerSync in browsers.

But we would have to wait for androidx.sqlite version 2.7.0 / room 3.0 to be released before we can merge that.

For builtin web support in the PowerSync SDK (without having to use Room as an underlying database), we can rely on the existing worker setup from the Dart SDK. The communication format between the main tab and the worker is stable, so the Kotlin SDK could re-use that worker. This would also allow us to run the sync client in a shared worker, which is important for multi-tab support.