feat(web): add admin users settings page (MS21-UI-001) (#573)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/web/src/app/(authenticated)/settings/page.tsx

@@ -196,6 +196,31 @@ const categories: CategoryConfig[] = [
       </svg>
     ),
   },
+  {
+    title: "Users",
+    description: "Invite, manage roles, and deactivate users across your workspaces.",
+    href: "/settings/users",
+    accent: "var(--ms-green-400)",
+    iconBg: "rgba(34, 197, 94, 0.12)",
+    icon: (
+      <svg
+        width="20"
+        height="20"
+        viewBox="0 0 20 20"
+        fill="none"
+        stroke="currentColor"
+        strokeWidth="1.5"
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        aria-hidden="true"
+      >
+        <circle cx="8" cy="7" r="2.5" />
+        <circle cx="13.5" cy="8.5" r="2" />
+        <path d="M3.5 16c0-2.5 2-4.5 4.5-4.5s4.5 2 4.5 4.5" />
+        <path d="M12 13.8c.5-.8 1.4-1.3 2.5-1.3 1.7 0 3 1.3 3 3" />
+      </svg>
+    ),
+  },
   {
     title: "Workspaces",
     description: