feat: Add new system for multi-selections.

crates/pikl-core/src/model/event.rs

@@ -20,6 +20,7 @@ pub enum Mode {
     #[default]
     Insert,
     Normal,
+    Visual,
 }
 
 /// A command the menu should process. Frontends and headless
@@ -37,6 +38,12 @@ pub enum Action {
     HalfPageUp(usize),
     HalfPageDown(usize),
     SetMode(Mode),
+    ToggleSelect,
+    SelectRange { start: usize, end: usize },
+    ClearSelections,
+    SelectAll,
+    UndoSelection,
+    RedoSelection,
     Confirm,
     Quicklist,
     Cancel,
@@ -53,7 +60,7 @@ pub enum Action {
 #[derive(Debug, Clone)]
 pub enum MenuEvent {
     StateChanged(ViewState),
-    Selected(Value),
+    Selected(Vec<(Value, usize)>),
     Quicklist(Vec<Value>),
     Cancelled,
 }
@@ -72,6 +79,8 @@ pub struct ViewState {
     pub total_items: usize,
     pub total_filtered: usize,
     pub mode: Mode,
+    pub selection_count: usize,
+    pub multi_enabled: bool,
     /// Monotonically increasing counter. Each call to
     /// `build_view_state()` bumps this, so frontends can
     /// detect duplicate broadcasts and skip redundant redraws.
@@ -87,6 +96,7 @@ pub struct VisibleItem {
     pub label: String,
     pub formatted_text: Option<String>,
     pub index: usize,
+    pub selected: bool,
 }
 
 /// Final outcome of [`crate::menu::MenuRunner::run`]. The
@@ -94,7 +104,7 @@ pub struct VisibleItem {
 #[must_use]
 #[derive(Debug)]
 pub enum MenuResult {
-    Selected { value: Value, index: usize },
+    Selected { items: Vec<(Value, usize)> },
     Quicklist { items: Vec<(Value, usize)> },
     Cancelled,
 }