Replace em dashes with hyphens across docs and comments

examples/bambu_commands_demo.rs

@@ -1,7 +1,7 @@
 //! Run with: cargo run --example bambu_commands_demo
 //!
 //! Round-trips both commands against the exact JSON from Bambu's real
-//! protocol — proves the plain hand-written struct + serde approach
+//! protocol - proves the plain hand-written struct + serde approach
 //! matches byte for byte, same as the proto-based version did, with none
 //! of the build.rs ceremony.
 
@@ -34,7 +34,7 @@ fn main() {
     println!("matches Bambu's shape: {}\n", actual == expected);
 
     // --- print report: arrives under "print", NOT "pushing" (pushall
-    // triggers this stream, it isn't a direct reply to it) — includes the
+    // triggers this stream, it isn't a direct reply to it) - includes the
     // full ams/xcam example, with one empty tray and one loaded tray, to
     // exercise the untagged Empty/Loaded split.
     let real_print_report = r#"{