Add tutorial overlay tour after welcome wizard

Semi-transparent dialog-based tour with 6 stops covering step
indicator, workflow selection, image adding, navigation, menu,
and a final ready message. Skippable at any time. State persisted
via tutorial_complete flag in AppConfig.

pixstrip-gtk/src/main.rs

@@ -3,6 +3,7 @@ mod processing;
 mod settings;
 mod step_indicator;
 mod steps;
+mod tutorial;
 mod welcome;
 mod wizard;
 

pixstrip-gtk/src/settings.rs

@@ -291,6 +291,7 @@ pub fn build_settings_dialog() -> adw::PreferencesDialog {
     dialog.connect_closed(move |_| {
         let new_config = AppConfig {
             first_run_complete: true,
+            tutorial_complete: true, // preserve if settings are being saved
             output_subfolder: subfolder_row.text().to_string(),
             output_fixed_path: None,
             overwrite_behavior: match overwrite_row.selected() {

pixstrip-gtk/src/tutorial.rs

@@ -0,0 +1,195 @@
+use adw::prelude::*;
+use gtk::glib;
+
+struct TourStop {
+    title: &'static str,
+    description: &'static str,
+    icon: &'static str,
+}
+
+const TOUR_STOPS: &[TourStop] = &[
+    TourStop {
+        title: "Step Indicator",
+        description: "This bar shows your progress through the wizard. Click any completed step to jump back to it.",
+        icon: "view-list-symbolic",
+    },
+    TourStop {
+        title: "Choose a Workflow",
+        description: "Start by picking a preset that matches what you need, or build a custom workflow from scratch.",
+        icon: "applications-graphics-symbolic",
+    },
+    TourStop {
+        title: "Add Your Images",
+        description: "Drag and drop files here, or use the Add button. You can paste from the clipboard too.",
+        icon: "image-x-generic-symbolic",
+    },
+    TourStop {
+        title: "Navigation",
+        description: "Use the Back and Next buttons to move between steps, or press Alt+Left/Right. Disabled steps are automatically skipped.",
+        icon: "go-next-symbolic",
+    },
+    TourStop {
+        title: "Main Menu",
+        description: "Access settings, keyboard shortcuts, processing history, and preset management from here.",
+        icon: "open-menu-symbolic",
+    },
+    TourStop {
+        title: "You're Ready!",
+        description: "That's everything you need to know. Each step also has a help button (?) in the header bar for detailed guidance.",
+        icon: "emblem-ok-symbolic",
+    },
+];
+
+/// Show the tutorial overlay if the user hasn't completed it yet.
+/// Called after the welcome wizard closes on first launch.
+pub fn show_tutorial_if_needed(window: &adw::ApplicationWindow) {
+    let config_store = pixstrip_core::storage::ConfigStore::new();
+    if let Ok(cfg) = config_store.load()
+        && cfg.tutorial_complete
+    {
+        return;
+    }
+
+    // Small delay to let the welcome dialog fully dismiss
+    let win = window.clone();
+    glib::timeout_add_local_once(std::time::Duration::from_millis(400), move || {
+        show_tour_dialog(&win, 0);
+    });
+}
+
+fn show_tour_dialog(window: &adw::ApplicationWindow, stop_index: usize) {
+    let stop = &TOUR_STOPS[stop_index];
+    let total = TOUR_STOPS.len();
+
+    let dialog = adw::Dialog::builder()
+        .title("Quick Tour")
+        .content_width(420)
+        .content_height(300)
+        .build();
+
+    let content = gtk::Box::builder()
+        .orientation(gtk::Orientation::Vertical)
+        .spacing(16)
+        .margin_top(24)
+        .margin_bottom(24)
+        .margin_start(24)
+        .margin_end(24)
+        .build();
+
+    // Progress dots
+    let dots_box = gtk::Box::builder()
+        .orientation(gtk::Orientation::Horizontal)
+        .spacing(6)
+        .halign(gtk::Align::Center)
+        .build();
+
+    for i in 0..total {
+        let dot = gtk::Label::builder()
+            .label(if i == stop_index { "\u{25CF}" } else { "\u{25CB}" })
+            .build();
+        if i == stop_index {
+            dot.add_css_class("accent");
+        } else {
+            dot.add_css_class("dim-label");
+        }
+        dots_box.append(&dot);
+    }
+    content.append(&dots_box);
+
+    // Icon
+    let icon = gtk::Image::builder()
+        .icon_name(stop.icon)
+        .pixel_size(64)
+        .halign(gtk::Align::Center)
+        .build();
+    icon.add_css_class("accent");
+    content.append(&icon);
+
+    // Title
+    let title = gtk::Label::builder()
+        .label(stop.title)
+        .css_classes(["title-2"])
+        .halign(gtk::Align::Center)
+        .build();
+    content.append(&title);
+
+    // Step counter
+    let counter = gtk::Label::builder()
+        .label(&format!("{} of {}", stop_index + 1, total))
+        .css_classes(["dim-label", "caption"])
+        .halign(gtk::Align::Center)
+        .build();
+    content.append(&counter);
+
+    // Description
+    let desc = gtk::Label::builder()
+        .label(stop.description)
+        .wrap(true)
+        .halign(gtk::Align::Center)
+        .justify(gtk::Justification::Center)
+        .build();
+    content.append(&desc);
+
+    // Buttons
+    let button_box = gtk::Box::builder()
+        .orientation(gtk::Orientation::Horizontal)
+        .spacing(12)
+        .halign(gtk::Align::Center)
+        .margin_top(8)
+        .build();
+
+    let skip_button = gtk::Button::builder()
+        .label("Skip Tour")
+        .build();
+    skip_button.add_css_class("flat");
+
+    let is_last = stop_index + 1 >= total;
+    let next_label = if is_last { "Get Started" } else { "Next" };
+    let next_button = gtk::Button::builder()
+        .label(next_label)
+        .build();
+    next_button.add_css_class("suggested-action");
+    next_button.add_css_class("pill");
+
+    button_box.append(&skip_button);
+    button_box.append(&next_button);
+    content.append(&button_box);
+
+    dialog.set_child(Some(&content));
+
+    // Wire skip - mark tutorial complete and close
+    {
+        let dlg = dialog.clone();
+        skip_button.connect_clicked(move |_| {
+            mark_tutorial_complete();
+            dlg.close();
+        });
+    }
+
+    // Wire next
+    {
+        let dlg = dialog.clone();
+        let win = window.clone();
+        next_button.connect_clicked(move |_| {
+            dlg.close();
+            if is_last {
+                mark_tutorial_complete();
+            } else {
+                let w = win.clone();
+                glib::idle_add_local_once(move || {
+                    show_tour_dialog(&w, stop_index + 1);
+                });
+            }
+        });
+    }
+
+    dialog.present(Some(window));
+}
+
+fn mark_tutorial_complete() {
+    let config_store = pixstrip_core::storage::ConfigStore::new();
+    if let Ok(mut cfg) = config_store.load() {
+        cfg.tutorial_complete = true;
+        let _ = config_store.save(&cfg);
+    }
+}

pixstrip-gtk/src/welcome.rs

@@ -10,14 +10,18 @@ pub fn show_welcome_if_first_launch(window: &adw::ApplicationWindow) {
 
     let dialog = build_welcome_dialog();
     let win = window.clone();
+    let win_for_present = window.clone();
     dialog.connect_closed(move |_| {
         let config = pixstrip_core::storage::ConfigStore::new();
         if let Ok(mut cfg) = config.load() {
             cfg.first_run_complete = true;
             let _ = config.save(&cfg);
         }
+
+        // Launch the tutorial tour after the welcome wizard
+        crate::tutorial::show_tutorial_if_needed(&win);
     });
-    dialog.present(Some(&win));
+    dialog.present(Some(&win_for_present));
 }
 
 fn build_welcome_dialog() -> adw::Dialog {