Managed to figure out how to use javascript on the plugin page by utilizing data-controller as found in other repos. Unsure how this is used, but appears to be how you can attach a js file to a div. Also implemented a basic state api to build off of in future.

Jellyfin.Plugin.MediaCleaner/Plugin.cs

@@ -2,11 +2,13 @@ using System;
 using System.Collections.Generic;
 using System.Globalization;
 using Jellyfin.Plugin.MediaCleaner.Configuration;
+using Jellyfin.Plugin.MediaCleaner.Data;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Common.Plugins;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Model.Plugins;
 using MediaBrowser.Model.Serialization;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Jellyfin.Plugin.MediaCleaner;
 
@@ -53,6 +55,11 @@ public class Plugin : BasePlugin<PluginConfiguration>, IHasWebPages
                 EmbeddedResourcePath = string.Format(CultureInfo.InvariantCulture, "{0}.Pages.home.html", GetType().Namespace),
                 EnableInMainMenu = true,
             },
+            new PluginPageInfo
+            {
+                Name = "media_cleaner_table.js",
+                EmbeddedResourcePath = string.Format(CultureInfo.InvariantCulture, "{0}.Pages.media_cleaner_table.js", GetType().Namespace),
+            }
         ];
     }
 }