feat: Add lead-worker model selection and real-time model display in GUI (#2964)

Co-authored-by: jack <jack@deck.local>

crates/goose-cli/src/commands/web.rs

@@ -589,6 +589,10 @@ async fn process_message_streaming(
                         // For now, we'll just log them
                         tracing::info!("Received MCP notification in web interface");
                     }
+                    Ok(AgentEvent::ModelChange { model, mode }) => {
+                        // Log model change
+                        tracing::info!("Model changed to {} in {} mode", model, mode);
+                    }
                     Err(e) => {
                         error!("Error in message stream: {}", e);
                         let mut sender = sender.lock().await;

crates/goose-cli/src/session/mod.rs

@@ -928,6 +928,12 @@ impl Session {
                                 }
                             }
                         }
+                        Some(Ok(AgentEvent::ModelChange { model, mode })) => {
+                            // Log model change if in debug mode
+                            if self.debug {
+                                eprintln!("Model changed to {} in {} mode", model, mode);
+                            }
+                        }
                         Some(Err(e)) => {
                             eprintln!("Error: {}", e);
                             drop(stream);