fix(acp): forward Pi model selection to the adapter (#10707)

crates/goose/src/providers/pi_acp.rs

@@ -58,6 +58,19 @@ impl ProviderDef for PiAcpProvider {
             let config = Config::global();
             let resolved_command = SearchPaths::builder().with_npm().resolve(PI_ACP_BINARY)?;
             let goose_mode = config.get_goose_mode().unwrap_or(GooseMode::Auto);
+            let model = config
+                .get_goose_model()
+                .unwrap_or_else(|_| ACP_CURRENT_MODEL.to_string());
+
+            // pi-acp advertises a "model" config option (MODEL_CONFIG_ID = "model")
+            // and applies it via setSessionModel → proc.setModel(provider, id).
+            // Wire it up so model selection from goose config or Buzz's set_model
+            // actually reaches the Pi Droid session instead of being silently dropped.
+            let session_config_options = if model == ACP_CURRENT_MODEL {
+                vec![]
+            } else {
+                vec![("model".to_string(), model)]
+            };
 
             let mode_mapping = HashMap::from([
                 (GooseMode::Auto, vec!["auto".to_string()]),
@@ -74,8 +87,8 @@ impl ProviderDef for PiAcpProvider {
                 work_dir: working_dir,
                 mcp_servers: extension_configs_to_mcp_servers(&extensions),
                 session_mode_id: mode_mapping[&goose_mode].first().cloned(),
-                session_config_options: vec![],
-                model_config_option_id: None,
+                session_config_options,
+                model_config_option_id: Some("model".to_string()),
                 mode_mapping,
                 notification_callback: None,
             };