chore: use a Conversation type (#3735)

crates/goose/src/token_counter.rs

@@ -6,7 +6,7 @@ use std::sync::Arc;
 use tiktoken_rs::CoreBPE;
 use tokio::sync::OnceCell;
 
-use crate::message::Message;
+use crate::conversation::message::Message;
 
 // Global tokenizer instance to avoid repeated initialization
 static TOKENIZER: OnceCell<Arc<CoreBPE>> = OnceCell::const_new();
@@ -380,7 +380,7 @@ pub async fn create_async_token_counter() -> Result<AsyncTokenCounter, String> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::message::{Message, MessageContent};
+    use crate::conversation::message::{Message, MessageContent};
     use rmcp::model::{Role, Tool};
     use rmcp::object;