Wire up step buttons: Browse, preset cards, output directory picker

- Browse Files button triggers win.add-files action
- Add More button in loaded state triggers win.add-files action
- Preset card activation (click) advances to next wizard step
- Custom workflow card activation advances to next step
- Choose output folder button opens folder dialog
- Output step shows current image count when navigated to
- Clean up dead code in update_count_in_box

pixstrip-gtk/src/app.rs

@@ -273,6 +273,17 @@ fn setup_window_actions(window: &adw::ApplicationWindow, ui: &WizardUi) {
         action_group.add_action(&action);
     }
 
+    // Choose output directory action
+    {
+        let window = window.clone();
+        let ui = ui.clone();
+        let action = gtk::gio::SimpleAction::new("choose-output", None);
+        action.connect_activate(move |_, _| {
+            open_output_chooser(&window, &ui);
+        });
+        action_group.add_action(&action);
+    }
+
     // Connect button clicks
     ui.back_button.connect_clicked({
         let action_group = action_group.clone();
@@ -316,6 +327,21 @@ fn navigate_to_step(ui: &WizardUi, target: usize) {
         ui.title.set_subtitle(&ui.pages[target].title());
     }
 
+    // Update dynamic content on certain steps
+    if target == 6 {
+        // Output step - update image count
+        let count = ui.state.loaded_files.borrow().len();
+        if let Some(page) = ui.pages.get(6) {
+            walk_widgets(&page.child(), &|widget| {
+                if let Some(row) = widget.downcast_ref::<adw::ActionRow>()
+                    && row.title().as_str() == "Images to process"
+                {
+                    row.set_subtitle(&format!("{} images", count));
+                }
+            });
+        }
+    }
+
     update_nav_buttons(&s, &ui.back_button, &ui.next_button);
 }
 
@@ -378,6 +404,36 @@ fn open_file_chooser(window: &adw::ApplicationWindow, ui: &WizardUi) {
     });
 }
 
+fn open_output_chooser(window: &adw::ApplicationWindow, ui: &WizardUi) {
+    let dialog = gtk::FileDialog::builder()
+        .title("Choose Output Folder")
+        .modal(true)
+        .build();
+
+    let ui = ui.clone();
+    dialog.select_folder(Some(window), gtk::gio::Cancellable::NONE, move |result| {
+        if let Ok(folder) = result
+            && let Some(path) = folder.path()
+        {
+            *ui.state.output_dir.borrow_mut() = Some(path.clone());
+            update_output_label(&ui, &path);
+        }
+    });
+}
+
+fn update_output_label(ui: &WizardUi, path: &std::path::Path) {
+    // Find the output step page (index 6) and update the output location subtitle
+    if let Some(page) = ui.pages.get(6) {
+        walk_widgets(&page.child(), &|widget| {
+            if let Some(row) = widget.downcast_ref::<adw::ActionRow>()
+                && row.title().as_str() == "Output Location"
+            {
+                row.set_subtitle(&path.display().to_string());
+            }
+        });
+    }
+}
+
 fn update_images_count_label(ui: &WizardUi, count: usize) {
     // Find the step-images page and switch its stack to "loaded" if we have files
     if let Some(page) = ui.pages.get(1)
@@ -393,13 +449,10 @@ fn update_images_count_label(ui: &WizardUi, count: usize) {
 }
 
 fn update_count_in_box(widget: &gtk::Widget, count: usize) {
-    // Walk the widget tree to find the heading label with "images" text
-    if let Some(label) = widget.downcast_ref::<gtk::Label>() {
-        if label.css_classes().iter().any(|c| c == "heading") {
-            let files = pixstrip_core::storage::PresetStore::new(); // just for format_bytes
-            let _ = files; // unused
-            label.set_label(&format!("{} images loaded", count));
-        }
+    if let Some(label) = widget.downcast_ref::<gtk::Label>()
+        && label.css_classes().iter().any(|c| c == "heading")
+    {
+        label.set_label(&format!("{} images loaded", count));
         return;
     }
     if let Some(bx) = widget.downcast_ref::<gtk::Box>() {