Feature request: Remove top-level await to enable bytecode compilation

[remorses]

Bun's bytecode compilation reduces startup from ~520ms to ~44ms but requires no top-level await. This is blocking https://github.com/sst/opencode/issues/4843

There are 3 top-level await locations:

yoga-layout WASM

https://github.com/sst/opentui/blob/5dbe0b4be9b647f2d10ac90b63acdecf1a6998d8/packages/core/src/index.ts#L18

yoga-layout uses async WebAssembly.instantiate() internally. Consider using FFI to native Yoga instead.

Platform import

https://github.com/sst/opentui/blob/5dbe0b4be9b647f2d10ac90b63acdecf1a6998d8/packages/core/src/zig.ts#L22

Can use sync require() instead.

Native lib path resolution

https://github.com/sst/opentui/blob/5dbe0b4be9b647f2d10ac90b63acdecf1a6998d8/packages/core/scripts/build.ts#L139-L142

Can use sync require.resolve() instead.

The platform import and native lib path are straightforward. Yoga is the main blocker.