Add favicon SVG and update base template to include it; add filterCategory to recommendations

templates/base.html

@@ -6,6 +6,7 @@
   <title>{% block title %}TasteEngine{% endblock %}</title>
   <link rel="preconnect" href="https://fonts.googleapis.com">
   <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap" rel="stylesheet">
+  <link rel="icon" type="image/svg+xml" href="/static/favicon.svg">
   <link rel="stylesheet" href="/static/css/style.css">
   <script src="https://cdn.jsdelivr.net/npm/alpinejs@3.14.1/dist/cdn.min.js" defer></script>
   <script src="https://unpkg.com/htmx.org@2.0.3/dist/htmx.min.js" defer></script>

templates/recommend.html

@@ -237,6 +237,7 @@
       nRecs: 10,
       showResults: false,
       coldStartDetected: false,
+      filterCategory: '',
       filterBrand: '',
       filterPriceMax: null,