perf: massive reduction in application bundle size

- Replaced Alpine.js and Turbolinks with lightweight vanilla JS event listeners
- Swapped HTMX CDN import for a custom 15-line native JS polyfill
- Removed Google Fonts ('Inter') in favor of the native system font stack
- Extracted repeated SVGs in list views into a `<defs>` block to shrink HTML
- Reduced dashboard pagination PAGE_SIZE from 50 to 25
- Minified Tailwind CSS output and enabled Gzip/Brotli via Flask-Compress

app/templates/partials/dashboard_list.html

@@ -1,3 +1,10 @@
+<svg xmlns="http://www.w3.org/2000/svg" style="display: none;">
+    <defs>
+        <path id="icon-clock" stroke-linecap="round" stroke-linejoin="round"
+            d="M12 8v4l3 3m9-3a9 9 0 1 1-18 0 9 9 0 0 1 18 0z" />
+        <path id="icon-chevron" stroke-linecap="round" stroke-linejoin="round" d="M8.25 4.5l7.5 7.5-7.5 7.5" />
+    </defs>
+</svg>
 <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-3">
     {% for reading in readings %}
     <a href="{{ url_for('reading.edit_reading', reading_id=reading.id) }}"
@@ -8,8 +15,7 @@
             <div class="flex items-center text-gray-400 text-xs mb-1">
                 <svg xmlns="http://www.w3.org/2000/svg" class="w-3.5 h-3.5 mr-1" fill="none" viewBox="0 0 24 24"
                     stroke="currentColor" stroke-width="2">
-                    <path stroke-linecap="round" stroke-linejoin="round"
-                        d="M12 8v4l3 3m9-3a9 9 0 1 1-18 0 9 9 0 0 1 18 0z" />
+                    <use href="#icon-clock"></use>
                 </svg>
                 <span title="{{ reading.local_timestamp.strftime('%d %b %Y, %I:%M %p') }}">
                     {{ reading.relative_timestamp }}
@@ -34,7 +40,7 @@
             <div class="text-gray-300">
                 <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2"
                     stroke="currentColor" class="h-4 w-4">
-                    <path stroke-linecap="round" stroke-linejoin="round" d="M8.25 4.5l7.5 7.5-7.5 7.5" />
+                    <use href="#icon-chevron"></use>
                 </svg>
             </div>
         </div>