Replace em dashes with hyphens across docs and comments

src/main.rs

@@ -19,8 +19,8 @@ async fn main() -> anyhow::Result<()> {
     tracing::info!(gateway_id = %config.gateway_id, farm_id = %config.farm_id, "starting continuum-proxy");
 
     // Two things run at once for now: the cloud uplink, and the go2rtc
-    // camera-restreaming process. More will join them later — printer
-    // discovery, the plate changer — as you build past src/printer/'s
+    // camera-restreaming process. More will join them later - printer
+    // discovery, the plate changer - as you build past src/printer/'s
     // stubs. `tokio::select!` runs both and stops as soon as either one
     // returns; both loop forever below, so in practice this runs until the
     // process is killed.