feat(core): Add input modes and half-page cursor movement.

crates/pikl-core/src/runtime/menu.rs

@@ -8,7 +8,7 @@ use std::sync::Arc;
 use tokio::sync::{broadcast, mpsc};
 
 use crate::error::PiklError;
-use crate::event::{Action, MenuEvent, MenuResult, ViewState, VisibleItem};
+use crate::event::{Action, MenuEvent, MenuResult, Mode, ViewState, VisibleItem};
 use crate::model::traits::Menu;
 use crate::navigation::Viewport;
 use serde_json::Value;
@@ -35,6 +35,7 @@ pub struct MenuRunner<M: Menu> {
     menu: M,
     viewport: Viewport,
     filter_text: Arc<str>,
+    mode: Mode,
     action_rx: mpsc::Receiver<Action>,
     event_tx: broadcast::Sender<MenuEvent>,
 }
@@ -55,6 +56,7 @@ impl<M: Menu> MenuRunner<M> {
             menu,
             viewport: Viewport::new(),
             filter_text: Arc::from(""),
+            mode: Mode::default(),
             action_rx,
             event_tx,
         };
@@ -100,6 +102,7 @@ impl<M: Menu> MenuRunner<M> {
             filter_text: Arc::clone(&self.filter_text),
             total_items: self.menu.total(),
             total_filtered: self.menu.filtered_count(),
+            mode: self.mode,
         }
     }
 
@@ -158,6 +161,18 @@ impl<M: Menu> MenuRunner<M> {
                 self.viewport.set_height(height as usize);
                 ActionOutcome::Broadcast
             }
+            Action::HalfPageUp(n) => {
+                self.viewport.half_page_up(n);
+                ActionOutcome::Broadcast
+            }
+            Action::HalfPageDown(n) => {
+                self.viewport.half_page_down(n);
+                ActionOutcome::Broadcast
+            }
+            Action::SetMode(m) => {
+                self.mode = m;
+                ActionOutcome::Broadcast
+            }
             Action::AddItems(values) => {
                 self.menu.add_raw(values);
                 self.run_filter();
@@ -166,6 +181,12 @@ impl<M: Menu> MenuRunner<M> {
         }
     }
 
+    /// Set the initial mode before running the event loop.
+    /// Used by `--start-mode` CLI flag.
+    pub fn set_initial_mode(&mut self, mode: Mode) {
+        self.mode = mode;
+    }
+
     /// Run the menu event loop. Consumes actions and
     /// broadcasts events.
     ///
@@ -617,6 +638,73 @@ mod tests {
         ));
     }
 
+    // -- New action variant tests --
+
+    #[test]
+    fn apply_half_page_down() {
+        let (mut m, _tx) = test_menu();
+        m.run_filter();
+        m.apply_action(Action::Resize { height: 4 });
+        let outcome = m.apply_action(Action::HalfPageDown(1));
+        assert!(matches!(outcome, ActionOutcome::Broadcast));
+        assert_eq!(m.viewport.cursor(), 2); // 4/2 = 2
+    }
+
+    #[test]
+    fn apply_half_page_up() {
+        let (mut m, _tx) = test_menu();
+        m.run_filter();
+        m.apply_action(Action::Resize { height: 4 });
+        m.apply_action(Action::HalfPageDown(1));
+        let outcome = m.apply_action(Action::HalfPageUp(1));
+        assert!(matches!(outcome, ActionOutcome::Broadcast));
+        assert_eq!(m.viewport.cursor(), 0);
+    }
+
+    #[test]
+    fn apply_set_mode_normal() {
+        let mut m = ready_menu();
+        let outcome = m.apply_action(Action::SetMode(Mode::Normal));
+        assert!(matches!(outcome, ActionOutcome::Broadcast));
+        assert_eq!(m.build_view_state().mode, Mode::Normal);
+    }
+
+    #[test]
+    fn apply_set_mode_insert() {
+        let mut m = ready_menu();
+        m.apply_action(Action::SetMode(Mode::Normal));
+        let outcome = m.apply_action(Action::SetMode(Mode::Insert));
+        assert!(matches!(outcome, ActionOutcome::Broadcast));
+        assert_eq!(m.build_view_state().mode, Mode::Insert);
+    }
+
+    #[test]
+    fn apply_set_mode_preserves_filter() {
+        let mut m = ready_menu();
+        m.apply_action(Action::UpdateFilter("al".to_string()));
+        let count_before = m.menu.filtered_count();
+        let filter_before = m.filter_text.clone();
+        m.apply_action(Action::SetMode(Mode::Normal));
+        assert_eq!(&*m.filter_text, &*filter_before);
+        assert_eq!(m.menu.filtered_count(), count_before);
+    }
+
+    #[test]
+    fn set_initial_mode_works() {
+        let (mut m, _tx) = test_menu();
+        m.set_initial_mode(Mode::Normal);
+        m.run_filter();
+        assert_eq!(m.build_view_state().mode, Mode::Normal);
+    }
+
+    #[test]
+    fn view_state_mode_after_switch() {
+        let mut m = ready_menu();
+        m.apply_action(Action::SetMode(Mode::Normal));
+        let vs = m.build_view_state();
+        assert_eq!(vs.mode, Mode::Normal);
+    }
+
     #[tokio::test]
     async fn actions_process_in_order_add_items_then_filter_then_confirm() {
         // AddItems + filter + confirm, all back-to-back.