Add format mapping to convert step, orientation controls to resize step

Add per-format mapping rows in convert step advanced options so each
input format can target a different output format. Move basic
orientation controls (rotate/flip) into the resize step per design doc
specification that these should be folded into the resize step.

pixstrip-gtk/src/steps/step_resize.rs

@@ -224,6 +224,38 @@ pub fn build_resize_page(state: &AppState) -> adw::NavigationPage {
 
     content.append(&mode_stack);
 
+    // Basic orientation adjustments (folded into resize step per design doc)
+    let orientation_group = adw::PreferencesGroup::builder()
+        .title("Orientation")
+        .description("Rotate and flip applied before resize")
+        .build();
+
+    let rotate_row = adw::ComboRow::builder()
+        .title("Rotate")
+        .subtitle("Rotation applied to all images")
+        .build();
+    let rotate_model = gtk::StringList::new(&[
+        "None",
+        "90 clockwise",
+        "180",
+        "270 clockwise",
+        "Auto-orient (from EXIF)",
+    ]);
+    rotate_row.set_model(Some(&rotate_model));
+    rotate_row.set_selected(cfg.rotation);
+
+    let flip_row = adw::ComboRow::builder()
+        .title("Flip")
+        .subtitle("Mirror the image")
+        .build();
+    let flip_model = gtk::StringList::new(&["None", "Horizontal", "Vertical"]);
+    flip_row.set_model(Some(&flip_model));
+    flip_row.set_selected(cfg.flip);
+
+    orientation_group.add(&rotate_row);
+    orientation_group.add(&flip_row);
+    content.append(&orientation_group);
+
     // Advanced options (AdwExpanderRow per design doc)
     let advanced_group = adw::PreferencesGroup::builder()
         .title("Advanced")
@@ -292,6 +324,18 @@ pub fn build_resize_page(state: &AppState) -> adw::NavigationPage {
             jc.borrow_mut().allow_upscale = row.is_active();
         });
     }
+    {
+        let jc = state.job_config.clone();
+        rotate_row.connect_selected_notify(move |row| {
+            jc.borrow_mut().rotation = row.selected();
+        });
+    }
+    {
+        let jc = state.job_config.clone();
+        flip_row.connect_selected_notify(move |row| {
+            jc.borrow_mut().flip = row.selected();
+        });
+    }
 
     scrolled.set_child(Some(&content));