feat: improve dashboard and connection workflows

- add connection delete endpoint and update connection list handling

- expand dashboard visualization behavior

- update helpers/header and project TODO tracking

app/templates/header.php

@@ -21,6 +21,7 @@
 
     <!-- JS -->
     <script src="/assets/js/app.js" defer></script>
+    <script src="/assets/js/dashboard.js" defer></script>
     <script src="/assets/js/svg-editor.js" defer></script>
     <script src="/assets/js/network-view.js" defer></script>