Replace em dashes with hyphens across docs and comments

examples/test_bambu_certs.rs

@@ -2,7 +2,7 @@
 //!
 //! Loads printers.toml (copy printers.example.toml to get started, fill in
 //! your real printers) and attempts a raw TLS handshake to each Bambu
-//! printer's MQTTS port (8883) — no MQTT protocol involved, just "does the
+//! printer's MQTTS port (8883) - no MQTT protocol involved, just "does the
 //! certificate verify". Prusa/Klipper entries are skipped; they don't have
 //! this trust question.
 
@@ -28,7 +28,7 @@ fn main() -> anyhow::Result<()> {
 
 fn report(name: &str, result: anyhow::Result<()>) {
     match result {
-        Ok(()) => println!("{name}: OK — certificate verified"),
-        Err(err) => println!("{name}: FAILED — {err}"),
+        Ok(()) => println!("{name}: OK - certificate verified"),
+        Err(err) => println!("{name}: FAILED - {err}"),
     }
 }