Function interpret_for_ui_sync 

pub fn interpret_for_ui_sync(input: &str) -> InterpreterResult

Interpret LOGOS imperative code synchronously (no async runtime needed).

The bytecode VM is the LIVE engine for the synchronous path (which is also the browser/WASM path). The tree-walker remains fully wired as: the async path (file I/O, sleep, mount), the shadow oracle in debug builds (every program the corpus runs is differentially checked against it), and the fallback for anything the VM compiler rejects.