Feat: Fav channel in localstorage

src/js/favorites.js

@@ -0,0 +1,35 @@
+// ── FAVORITES ─────────────────────────────────────────────────────────────────
+let favorites = new Set(JSON.parse(localStorage.getItem('gridtv-favorites') || '[]'));
+
+function saveFavorites() {
+  localStorage.setItem('gridtv-favorites', JSON.stringify([...favorites]));
+}
+
+function toggleFavorite(chId, btn) {
+  if (favorites.has(chId)) {
+    favorites.delete(chId);
+    btn.classList.remove('is-fav');
+    btn.title = L.fav_add;
+  } else {
+    favorites.add(chId);
+    btn.classList.add('is-fav');
+    btn.title = L.fav_remove;
+  }
+  saveFavorites();
+  renderAll();
+}
+
+function makeFavBtn(chId) {
+  const btn = document.createElement('button');
+  btn.className = 'fav-btn' + (favorites.has(chId) ? ' is-fav' : '');
+  btn.title = favorites.has(chId) ? L.fav_remove : L.fav_add;
+  btn.textContent = '★';
+  btn.addEventListener('click', e => { e.stopPropagation(); toggleFavorite(chId, btn); });
+  return btn;
+}
+
+function sortedChannels(list) {
+  const favs = list.filter(ch => favorites.has(ch.id));
+  const rest  = list.filter(ch => !favorites.has(ch.id));
+  return { favs, rest };
+}