feat(server): build axum web server for licensing, landing page, and updates

server/templates/404.html

@@ -0,0 +1,83 @@
+{% extends "base.html" %}
+
+{% block title %}Page Not Found — CleanCopy{% endblock %}
+
+{% block head %}
+<style>
+  .error-container {
+    text-align: center;
+  }
+
+  .error-icon {
+    font-size: 4rem;
+    margin-bottom: 1rem;
+  }
+
+  h1 {
+    font-size: 2rem;
+    margin-bottom: 1rem;
+    color: var(--color-accent);
+  }
+
+  .error-message {
+    background: var(--color-bg-elevated);
+    border: 1px solid var(--color-border-subtle);
+    border-radius: 8px;
+    padding: 1.5rem;
+    margin: 2rem auto;
+    text-align: left;
+  }
+
+  .error-message p {
+    margin-bottom: 0;
+    color: var(--color-text-primary);
+  }
+
+  .error-hint {
+    color: var(--color-text-secondary);
+    font-size: 0.9rem;
+    margin-top: 1.5rem;
+  }
+
+  .error-actions {
+    margin-top: 2rem;
+  }
+
+  .error-actions a {
+    display: inline-block;
+    padding: 0.75rem 1.5rem;
+    background: var(--color-accent);
+    color: var(--color-accent-text-on);
+    text-decoration: none;
+    border-radius: 8px;
+    font-weight: bold;
+  }
+
+  .error-actions a:hover {
+    background: var(--color-accent-hover);
+    text-decoration: none;
+  }
+</style>
+{% endblock %}
+
+{% block content %}
+<div class="error-container">
+  <div class="error-icon">∅</div>
+  <h1>Page Not Found</h1>
+
+  <div class="error-message">
+    <p>
+      This page has been cleaned from existence. It was probably full of
+      tracking parameters.
+    </p>
+  </div>
+
+  <p class="error-hint">
+    The URL you visited doesn't exist, or may have been moved.
+  </p>
+
+  <div class="error-actions">
+    <a href="/">Back to Home</a>
+  </div>
+</div>
+{% endblock %}