feat(ui): ui-shell header with tool links, mobile side nav, Youreka logo

- header: Carbon ui-shell (cds-header) with the Youreka logo (from
  idid-enterprise-portal), Image Cropper / Fingerprint Agent nav items
  (aria-current on the active tool), the agent status tag on the wizard,
  and the operator chip + Sign out on desktop
- mobile: cds-side-nav (logo above the items, both tools, a divider, then
  Sign out) toggled by the ui-shell menu button; account actions move out
  of the header below 1056px, the nav is hidden at desktop widths
- the header is built once in server.js (appHeader) and injected into the
  landing, both tools and error pages — no per-page duplication
- removed my duplicate menu-button toggle: ui-shell coordinates the menu
  button and side nav itself (the duplicate cancelled it out)
- fixes: 'cds-header' was hidden by a selector-list typo
  (cds-header, cds-side-nav:not(:defined)); the collapsed side nav no
  longer captures taps

Tools banner logo asset added (public/assets/youreka-logo.png).

tools/public/assets/fp/app.js

@@ -41,10 +41,6 @@ Vue.config.ignoredElements = [/^cds-/];
     },
 
     computed: {
-      initials: function () {
-        var n = (this.session && (this.session.firstName || this.session.phone)) || '?';
-        return n.slice(0, 2).toUpperCase();
-      },
       maxStage: function () { return MAX_STAGE; },
       bothCaptured: function () {
         return this.fingers['right-thumb'].status === 'done' &&
@@ -139,17 +135,27 @@ Vue.config.ignoredElements = [/^cds-/];
         });
       },
 
+      /** The agent status tag lives in the server-rendered header. */
+      renderAgentTag: function () {
+        var el = document.getElementById('agent-status');
+        if (!el) return;
+        el.textContent = this.agent.connected ? 'Agent connected' : 'Agent offline';
+        el.setAttribute('type', this.agent.connected ? 'green' : 'red');
+        el.setAttribute('title', this.agent.version ? 'fpagent ' + this.agent.version : '');
+      },
+
       connectAgent: function () {
         var self = this;
         this.socket = io(this.session.agentUrl, { reconnectionDelayMax: 5000 });
 
-        this.socket.on('connect', function () { self.agent.connected = true; });
-        this.socket.on('disconnect', function () { self.agent.connected = false; });
-        this.socket.on('connect_error', function () { self.agent.connected = false; });
+        this.socket.on('connect', function () { self.agent.connected = true; self.renderAgentTag(); });
+        this.socket.on('disconnect', function () { self.agent.connected = false; self.renderAgentTag(); });
+        this.socket.on('connect_error', function () { self.agent.connected = false; self.renderAgentTag(); });
 
         this.socket.on('agent-hello', function (data) {
           self.agent.version = (data && data.version) || '';
           self.agent.captureAgentId = (data && data.captureAgentId) || '';
+          self.renderAgentTag();
         });
 
         this.socket.on('fprint-enroll-status', function (data) {

tools/public/assets/fp/index.html

@@ -9,6 +9,7 @@
   <link rel="stylesheet" href="/assets/style.css">
   <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><rect width='24' height='24' rx='4' fill='%230f62fe'/><path d='M12 5a6 6 0 0 0-6 6c0 2.6.8 4.1 1.5 5.2' fill='none' stroke='white' stroke-width='1.6' stroke-linecap='round'/><path d='M15.5 19a7.5 7.5 0 0 0 3-9.7A6 6 0 0 0 7.1 7.9' fill='none' stroke='white' stroke-width='1.6' stroke-linecap='round'/><path d='M9.5 18.5a5.5 5.5 0 0 1-.8-7.6 3.8 3.8 0 0 1 7.2 1.5 4.3 4.3 0 0 1-3.4 4.6' fill='none' stroke='white' stroke-width='1.6' stroke-linecap='round'/></svg>">
   <script src="https://cdn.socket.io/4.4.0/socket.io.min.js" integrity="sha384-1fOn6VtTq3PWwfsOrk45LnYcGosJwzMHv+Xh/Jx5303FVOXzEnw0EpLv30mtjmlj" crossorigin="anonymous"></script>
+  <script type="module" src="https://1.www.s81c.com/common/carbon/web-components/version/v2.50.0/ui-shell.min.js"></script>
   <script type="module" src="https://1.www.s81c.com/common/carbon/web-components/version/v2.50.0/button.min.js"></script>
   <script type="module" src="https://1.www.s81c.com/common/carbon/web-components/version/v2.50.0/notification.min.js"></script>
   <script type="module" src="https://1.www.s81c.com/common/carbon/web-components/version/v2.50.0/progress-bar.min.js"></script>
@@ -16,25 +17,7 @@
 </head>
 <body class="app">
 <div id="app">
-  <nav class="nav">
-    <div class="container">
-      <a class="brand" href="/">
-        <span class="brand-mark">
-          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M12 2a8 8 0 0 0-8 8c0 3.5 1 5.5 2 7"/><path d="M16 21a10 10 0 0 0 4-13 8 8 0 0 0-15.7-1"/><path d="M8 21a8 8 0 0 1-1-11 5 5 0 0 1 9.7 1.4A6 6 0 0 1 12 17"/><path d="M12 21a4 4 0 0 0 4-4 4 4 0 0 0-1.2-2.9"/></svg>
-        </span>
-        YOUreka <small>Tools</small>
-      </a>
-      <div class="nav-right" v-cloak v-if="session">
-        <cds-tag v-bind:type="agent.connected ? 'green' : 'red'"
-                 v-bind:title="agent.version ? 'fpagent ' + agent.version : ''">{{ agent.connected ? 'Agent connected' : 'Agent offline' }}</cds-tag>
-        <span class="user-chip">
-          <span class="avatar">{{ initials }}</span>
-          {{ session.firstName || session.phone }}
-        </span>
-        <a class="linklike" href="/auth/logout">Sign out</a>
-      </div>
-    </div>
-  </nav>
+  <!--app-header-->
 
   <main class="container" v-cloak v-if="session">
     <div class="page-head">