feat(iced): add keyboard shortcuts for selection operations

hcie-iced-app/crates/hcie-iced-gui/src/app.rs

@@ -379,6 +379,9 @@ pub enum Message {
     SelectionDragStart(f32, f32),
     SelectionDragMove(f32, f32),
     SelectionDragEnd,
+    SelectAll,
+    Deselect,
+    SelectInverse,
 
     // ── Selection transform ─────────────────────────────
     TransformDragStart(f32, f32),
@@ -1975,6 +1978,19 @@ impl HcieIcedApp {
                     }
                 }
             }
+            Message::SelectAll => {
+                let w = self.documents[self.active_doc].engine.canvas_width() as f32;
+                let h = self.documents[self.active_doc].engine.canvas_height() as f32;
+                self.documents[self.active_doc].selection_rect = Some((0.0, 0.0, w, h));
+            }
+            Message::Deselect => {
+                self.documents[self.active_doc].selection_rect = None;
+            }
+            Message::SelectInverse => {
+                self.documents[self.active_doc].engine.selection_invert();
+                self.refresh_composite_if_needed();
+                return Task::perform(async {}, |_| Message::CompositeRefresh);
+            }
 
             // ── Selection transform ────────────────────────
             Message::TransformDragStart(x, y) => {
@@ -3000,6 +3016,10 @@ impl HcieIcedApp {
     /// - Ctrl+O: Open
     /// - Ctrl+C: Copy
     /// - Ctrl+V: Paste
+    /// - Ctrl+X: Cut
+    /// - Ctrl+A: Select All
+    /// - Ctrl+D: Deselect
+    /// - Ctrl+Shift+I: Inverse Selection
     /// - Escape: Close dialog
     pub fn subscription(&self) -> iced::Subscription<Message> {
         let keyboard = iced::keyboard::on_key_press(|key, modifiers| {
@@ -3042,6 +3062,18 @@ impl HcieIcedApp {
                 iced::keyboard::Key::Character(ref c) if c.as_str() == "x" && ctrl && !shift => {
                     Some(Message::CopyImage) // TODO: cut
                 }
+                // Ctrl+A = Select All
+                iced::keyboard::Key::Character(ref c) if c.as_str() == "a" && ctrl && !shift => {
+                    Some(Message::SelectAll)
+                }
+                // Ctrl+D = Deselect
+                iced::keyboard::Key::Character(ref c) if c.as_str() == "d" && ctrl && !shift => {
+                    Some(Message::Deselect)
+                }
+                // Ctrl+Shift+I = Inverse Selection
+                iced::keyboard::Key::Character(ref c) if c.as_str() == "i" && ctrl && shift => {
+                    Some(Message::SelectInverse)
+                }
                 // Escape = close menu, cancel dialog, deselect, or cancel crop
                 iced::keyboard::Key::Named(iced::keyboard::key::Named::Escape) => {
                     Some(Message::MenuClose) // Crop cancel handled in update()