Refactor: Remove jQuery dependency and use vanilla JavaScript.remove-jquery

This commit removes jQuery and the jQuery.tmpl plugin from the frontend,
refactoring all JavaScript code in static/ui.js and relevant HTML files
to use vanilla JavaScript APIs.

Key changes include:
- Replaced jQuery selectors ($) with document.querySelector/querySelectorAll.
- Replaced jQuery DOM manipulation methods with native equivalents (classList,
  style, appendChild, etc.).
- Replaced jQuery event handling (ready, on, keydown) with
  addEventListener.
- Replaced $.getJSON with the fetch API.
- Replaced $.each with Array.prototype.forEach.
- Implemented a custom vanilla JS templating function (`renderTemplate`) to
  replace jquery.tmpl.js functionality, including support for variable
  interpolation, conditionals (if/else), and raw HTML rendering.
- Updated Backbone.js views to handle their own DOM interactions and event
  delegation using vanilla JS, removing the `events` hash and using
  manual event listener attachment in `render` or `attachEvents` methods.
- Removed script tags for jquery and jquery.tmpl from HTML files.
- Replaced inline jQuery calls in HTML onclick attributes with vanilla JS.
- Added a minimal Backbone.$ shim to static/ui.js to address an
  `instanceof` TypeError in Backbone's _setElement method when jQuery
  is not present. This ensures Backbone's internal DOM handling and
  type checks can function correctly.

1 files changed, 2 insertions, 2 deletions

diff --git a/static/ui.html b/static/ui.html
index 5701d47..93ab09d 100644
--- a/static/ui.html
+++ b/static/ui.html
@@ -18,11 +18,11 @@
       <div id="filters">
 
         <div id="controls"></div>
-        <h4 onclick="document.querySelector('#tags').style.display = document.querySelector('#tags').style.display === 'none' ? '' : 'none';">Tags</h4>        
+        <h4 onclick="document.querySelector('#tags').style.display = document.querySelector('#tags').style.display === 'none' ? '' : 'none';">Tags</h4>
         <ul id="tags" style="display: none;">
         </ul>
         
-        <h4 onclick="document.querySelector('#feeds').style.display = document.querySelector('#feeds').style.display === 'none' ? '' : 'none';">Feeds</h4>        
+        <h4 onclick="document.querySelector('#feeds').style.display = document.querySelector('#feeds').style.display === 'none' ? '' : 'none';">Feeds</h4>
         <ul id="feeds" style="display: none;">
         </ul>