catalog: add required start() activating native Scroll navigation via Navigator

plugin.js

@@ -135,6 +135,28 @@
             return html;
         };
 
+        // Required by ActivitySlide contract. Activates navigation the same way the
+        // native catalog (Main) does: Scroll owns focus/scroll, Controller just drives
+        // Navigator. Scroll auto-scrolls the focused card into view.
+        this.start = function () {
+            var started = false;
+            Lampa.Controller.add('content', {
+                toggle: function () {
+                    var first = $('.mymovies .card.selector')[0];
+                    if (first && !started) {
+                        started = true;
+                        Lampa.Controller.collectionFocus(first, $('.mymovies'));
+                    }
+                },
+                left: function () { if (Navigator.canmove('left')) Navigator.move('left'); else Lampa.Controller.toggle('menu'); },
+                right: function () { Navigator.move('right'); },
+                up: function () { Navigator.move('up'); },
+                down: function () { Navigator.move('down'); },
+                back: function () { Lampa.Activity.backward(); }
+            });
+            Lampa.Controller.toggle('content');
+        };
+
         // Build each card and append through the native Scroll (handles focus + scroll).
         function renderMovies(movies) {
             movies.forEach(function (m) {