Refactor database handling to require PostgreSQL connection, removing fallback to JSON. Implement error handling for database unavailability in key files. Update .env.example to reflect mandatory DATABASE_URL for local development. Remove Firebase configuration and related code from the project.

assets/fc-local.js

@@ -0,0 +1,62 @@
+// Local-only favorites and dietary goal (no cloud backend).
+(function (global) {
+  var FAV_KEY = 'fc_fav_slugs';
+  var GOAL_KEY = 'fc_diet_goal';
+
+  function readJson(key, fallback) {
+    try {
+      var raw = global.localStorage.getItem(key);
+      if (!raw) return fallback;
+      return JSON.parse(raw);
+    } catch (e) {
+      return fallback;
+    }
+  }
+
+  function writeJson(key, value) {
+    try {
+      global.localStorage.setItem(key, JSON.stringify(value));
+    } catch (e) {
+      /* ignore quota errors */
+    }
+  }
+
+  global.fcLocal = {
+    getFavorites: function () {
+      var list = readJson(FAV_KEY, []);
+      return Array.isArray(list) ? list : [];
+    },
+    hasFavorite: function (slug) {
+      return this.getFavorites().indexOf(slug) !== -1;
+    },
+    toggleFavorite: function (slug) {
+      var list = this.getFavorites();
+      var idx = list.indexOf(slug);
+      if (idx === -1) {
+        list.push(slug);
+      } else {
+        list.splice(idx, 1);
+      }
+      writeJson(FAV_KEY, list);
+      return list;
+    },
+    getGoal: function () {
+      try {
+        return global.localStorage.getItem(GOAL_KEY) || '';
+      } catch (e) {
+        return '';
+      }
+    },
+    setGoal: function (goal) {
+      try {
+        if (goal) {
+          global.localStorage.setItem(GOAL_KEY, goal);
+        } else {
+          global.localStorage.removeItem(GOAL_KEY);
+        }
+      } catch (e) {
+        /* ignore */
+      }
+    }
+  };
+})(window);