Remove max-width cap so host wells fill the viewport

The max-w-7xl (1280px) constraint left too much dead space between
the host wells and the window edges. Remove it so the layout uses
all available width.

src/main.js

@@ -425,7 +425,7 @@ function hostRowHTML(host, index) {
 function buildUI(state) {
     const app = document.getElementById("app");
     app.innerHTML = `
-    <div class="max-w-7xl mx-auto px-2 py-8">
+    <div class="mx-auto px-4 py-8">
       <header class="mb-8">
         <div class="flex items-center justify-between mb-4">
           <h1 class="text-3xl font-bold text-white">NetWatch</h1>