Function compile 

pub fn compile(source: &str, platform: Platform) -> CompileResult

Compile a single in-memory Bynk source to a JavaScript module graph for the given platform (the playground passes [Platform::Browser]). Pure: no filesystem, no tsc. The in-process Bundle subset only; programs that reach Workers/Cloudflare-only shapes are reported as diagnostics (slice-2 platform lock), never silently mis-compiled.