feat(tui): expose current model in turn metadata

crates/tui/src/core/engine.rs

@@ -1206,7 +1206,10 @@ impl Engine {
             .map(|s| s.trim().to_string())
             .filter(|s| !s.is_empty());
 
-        let mut lines = vec![format!("Current local date: {today}")];
+        let mut lines = vec![
+            format!("Current local date: {today}"),
+            format!("Current model: {routed_model}"),
+        ];
         if auto_model {
             lines.push(format!("Auto model route: {routed_model}"));
         }

crates/tui/src/core/engine/tests.rs

@@ -1877,6 +1877,7 @@ fn working_set_reaches_model_as_turn_metadata() {
 fn turn_metadata_includes_current_local_date_without_working_set() {
     let tmp = tempdir().expect("tempdir");
     let config = EngineConfig {
+        model: "deepseek-v4-flash".to_string(),
         workspace: tmp.path().to_path_buf(),
         ..Default::default()
     };
@@ -1896,6 +1897,7 @@ fn turn_metadata_includes_current_local_date_without_working_set() {
     let today = chrono::Local::now().format("%Y-%m-%d").to_string();
     assert!(text.starts_with("<turn_meta>\n"));
     assert!(text.contains(&format!("Current local date: {today}")));
+    assert!(text.contains("Current model: deepseek-v4-flash"));
 }
 
 #[test]
@@ -1919,6 +1921,7 @@ fn turn_metadata_includes_auto_model_route() {
         panic!("expected text metadata block");
     };
 
+    assert!(text.contains("Current model: deepseek-v4-pro"));
     assert!(text.contains("Auto model route: deepseek-v4-pro"));
     assert!(text.contains("Auto reasoning effort: max"));
     assert!(!text.contains("debug this regression"));

docs/MODES.md

@@ -9,6 +9,10 @@ Model selection is separate. `--model auto` and `/model auto` route each turn to
 a concrete model and thinking level; they are not TUI modes and are not part of
 the `Tab` cycle.
 
+Each user turn includes a small `<turn_meta>` block with the current local date
+and the concrete model sent to the provider. When `--model auto` is active, the
+same block also records that the model was auto-routed.
+
 ## TUI Modes
 
 Press `Tab` to complete composer menus, queue a draft as a next-turn follow-up