feat: catalog style toggle (classic/new) with admin mode & favorites

catalog_favorites.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS catalog_favorites (
+    user_id INT NOT NULL,
+    type ENUM('offer', 'page') NOT NULL,
+    target_id INT NOT NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (user_id, type, target_id)
+);