CLI snapshot takes --in; an unknown command suggests close ids (#1301)

snapshot starts from --in (a design or STEP file) with the script on top, as run does, and refuses options it doesn't take; an unknown command id names the closest registered ids.

crates/engine/src/lib.rs

@@ -43,7 +43,7 @@ pub const MAX_LINE: usize = 16 << 20;
 
 #[derive(Debug, thiserror::Error)]
 pub enum EngineError {
-    #[error("unknown command `{0}`")]
+    #[error("unknown command `{0}`{hint}", hint = cmd::did_you_mean(.0))]
     UnknownCommand(String),
     #[error("`{0}` is not available right now: {1}")]
     Disabled(String, String),