Macro uniffi_bridged_engine 

macro_rules! uniffi_bridged_engine {
    ($name:ident, $guid:ty) => { ... };
}

Generates a UniFFI-exposable bridged engine newtype around BridgedEngineWrapper, removing the ~100 lines of identical facade boilerplate each consuming crate used to hand-write.

Usage (invoke in the module the crate’s UDL interface resolves against):

sync15::uniffi_bridged_engine!(LoginsBridgedEngine, String);
sync15::uniffi_bridged_engine!(TabsBridgedEngine, sync_guid::Guid);

$guid is the element type the crate’s UDL lowers set_uploaded‘s ids to (String for logins’ sequence<string>, sync_guid::Guid for the tabs and webext-storage custom-type sequences). The generated methods return anyhow::Result, which the crate’s UDL [Throws=...] maps to its error type via the existing impl From<anyhow::Error>.

The macro always emits prepare_for_sync; a crate whose UDL doesn’t declare it (logins) simply leaves that inherent method unbound, which is harmless.