Added admin-only page, and updated server backend to actually work with

admin stuff (IsAdmin).

Pages/Admin.php

@@ -0,0 +1,39 @@
+<?php
+
+$PageTitle = "Admin";
+$PageSection = "Admin";
+
+
+?>
+
+<!DOCTYPE html>
+
+<html lang="en" data-palette="CatppuccinMocha">
+    <?php require __DIR__ . "/Bits/Head.php"; ?>
+
+    <body>
+        <?php require __DIR__ . "/Bits/Navbar.php"; ?>
+
+        <main class="MainContainer">
+            <h1>Admin</h1>
+
+            <p
+                id="AdminAccessMessage"
+                class="PageMessage"
+                aria-live="polite"
+            >
+                Checking admin access...
+            </p>
+
+            <div
+                id="AdminContent"
+                hidden
+            >
+                <p>
+                    Admin access verified. Garden content
+                    editors will live here.
+                </p>
+            </div>
+        </main>
+    </body>
+</html>

Pages/Bits/Navbar.php

@@ -29,4 +29,25 @@ $NavbarPages = [
             >
         </a>
     <?php endforeach; ?>
+
+    <a
+        id="AdminNavbarLink"
+        class="NavbarLink"
+        href="/Pages/Admin.html"
+        aria-label="Admin"
+        title="Admin"
+        <?= ($PageSection ?? $PageTitle ?? "") === "Admin" ? 'aria-current="page"' : "" ?>
+        hidden
+    >
+        <img
+            class="NavbarIcon"
+            src="/Assets/Img/Icon.png"
+            alt=""
+        >
+    </a>
 </nav>
+
+<script
+    src="/Scripts/Garden/AdminAccess.js"
+    defer
+></script>