feat(web): topologies nav entry and /mazenet route guard

New /topologies page lists topologies; a bare /mazenet now redirects
there since the editor has no meaning without ?topology=<id>. Wizard
picks up a note style + tweaked copy.

decnet_web/src/App.tsx

@@ -13,6 +13,15 @@ import RemoteUpdates from './components/RemoteUpdates';
 import SwarmHosts from './components/SwarmHosts';
 import AgentEnrollment from './components/AgentEnrollment';
 import MazeNET from './components/MazeNET/MazeNET';
+import TopologyList from './components/TopologyList/TopologyList';
+
+/* Guard the /mazenet route so it's always bound to a real topology.
+ * Bare /mazenet → /topologies; ?topology=<id> → editor. */
+function MazeNETRoute() {
+  const qs = typeof window !== 'undefined' ? window.location.search : '';
+  const hasId = new URLSearchParams(qs).get('topology');
+  return hasId ? <MazeNET /> : <Navigate to="/topologies" replace />;
+}
 
 function isTokenValid(token: string): boolean {
   try {
@@ -63,7 +72,8 @@ function App() {
         <Routes>
           <Route path="/" element={<Dashboard searchQuery={searchQuery} />} />
           <Route path="/fleet" element={<DeckyFleet />} />
-          <Route path="/mazenet" element={<MazeNET />} />
+          <Route path="/topologies" element={<TopologyList />} />
+          <Route path="/mazenet" element={<MazeNETRoute />} />
           <Route path="/live-logs" element={<LiveLogs />} />
           <Route path="/bounty" element={<Bounty />} />
           <Route path="/attackers" element={<Attackers />} />

decnet_web/src/components/Layout.tsx

@@ -43,6 +43,7 @@ const Layout: React.FC<LayoutProps> = ({ children, onLogout, onSearch }) => {
         <nav className="sidebar-nav">
           <NavItem to="/" icon={<LayoutDashboard size={20} />} label="Dashboard" open={sidebarOpen} />
           <NavItem to="/fleet" icon={<Server size={20} />} label="Decoy Fleet" open={sidebarOpen} />
+          <NavItem to="/topologies" icon={<Network size={20} />} label="Topologies" open={sidebarOpen} />
           <NavItem to="/mazenet" icon={<Network size={20} />} label="MazeNET" open={sidebarOpen} />
           <NavItem to="/live-logs" icon={<Terminal size={20} />} label="Live Logs" open={sidebarOpen} />
           <NavItem to="/bounty" icon={<Archive size={20} />} label="Bounty" open={sidebarOpen} />

decnet_web/src/components/TopologyList/CreateTopologyWizard.css

@@ -176,6 +176,27 @@
   accent-color: var(--violet);
 }
 
+.ctw-note {
+  padding: 10px 12px;
+  border: 1px dashed var(--violet);
+  color: var(--text-color);
+  font-size: 0.7rem;
+  line-height: 1.5;
+  letter-spacing: 0.3px;
+  background: var(--violet-tint-10, rgba(238, 130, 238, 0.08));
+}
+.ctw-note strong {
+  color: var(--violet);
+  letter-spacing: 1px;
+  margin-right: 6px;
+}
+.ctw-note code {
+  background: #000;
+  padding: 1px 5px;
+  font-family: var(--font-mono);
+  color: var(--matrix, #33ff66);
+}
+
 .ctw-error {
   padding: 10px 12px;
   border: 1px solid var(--alert, #e74c3c);

decnet_web/src/components/TopologyList/CreateTopologyWizard.tsx

@@ -255,6 +255,14 @@ const CreateTopologyWizard: React.FC<Props> = ({ open, onClose, onCreated }) =>
             <>
               <div className="ctw-label">Where should this topology run?</div>
               <div className="ctw-grid-3">{step0Cards}</div>
+              <div className="ctw-note">
+                <strong>HEADS UP:</strong> the gateway decky publishes its
+                service ports on the target host (e.g. <code>0.0.0.0:22</code>{' '}
+                for SSH). Move any host-side daemons off collision ports
+                BEFORE deploying — otherwise docker will fail with{' '}
+                <code>address already in use</code>. On a fresh VPS this
+                usually means relocating sshd to <code>2222</code>.
+              </div>
             </>
           )}