fix: metrics on posthog (#6024)

Co-authored-by: Zane Staggs <zane@squareup.com>
Co-authored-by: Zane <75694352+zanesq@users.noreply.github.com>

crates/goose/src/session/session_manager.rs

@@ -120,8 +120,8 @@ pub struct SessionUpdateBuilder {
 #[derive(Serialize, ToSchema, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct SessionInsights {
-    total_sessions: usize,
-    total_tokens: i64,
+    pub total_sessions: usize,
+    pub total_tokens: i64,
 }
 
 impl SessionUpdateBuilder {
@@ -887,6 +887,7 @@ impl SessionStorage {
             .await?;
 
         tx.commit().await?;
+        crate::posthog::emit_session_started();
         Ok(session)
     }