Wire InfoCommand through as one real, runnable example

BambuRequest::Info(InfoCommand) is now live (was commented out) —
examples/bambu_protocol_demo.rs constructs one, serializes it, and prints
it next to Bambu's real wire JSON for comparison. Run it and copy this
exact shape (proto message -> use it here -> add an enum variant) for
every other command.

src/printer/mod.rs

@@ -29,10 +29,12 @@
 //! `tokio::spawn`, not yet).
 
 mod bambu;
+mod bambu_protocol;
 mod klipper;
 mod prusa;
 
 pub use bambu::{BambuGenericPrinter, BambuTls, BambuV1Printer, BambuV2Printer};
+pub use bambu_protocol::{BambuReport, BambuRequest};
 pub use klipper::KlipperPrinter;
 pub use prusa::{PrusaLinkPrinter, PrusaSerialPrinter};