Add boot splash; separate Systems Operational and Security icons

Loading indicator:
- Branded boot splash (Hub logo inside an accent spinner ring,
  "Starting The Hub") covers the shell while the first services
  data loads, then fades out once the welcome dashboard has
  rendered; never blocks longer than 25s and reassures the user
  after 8s (message about post-reboot delays)
- Fire the network and update checks before the first services
  render so the dashboard cards are current at first paint
- Sidebar Update button now adopts the last known update state
  when built (order-independent), and the welcome dashboard
  re-renders when the update state changes

Icons:
- New monochrome g-pulse glyph (activity line) for Systems
  Operational: welcome card, dialog header, and System Status
  section — the shield no longer doubles as Security
- Tech Support / Security dialog header gets a standard chip;
  Security shows the shield chip with a plain "Security" title
  (no emoji), and the shared dialog title now resets correctly
  when reopening Tech Support after Security

app/sovran_systemsos_web/templates/index.html

@@ -111,6 +111,11 @@
         <path d="M8.6 12l2.4 2.4 4.4-4.6"/>
       </g>
     </symbol>
+    <!-- Systems Operational: activity pulse (system health) — distinct from
+         the Security shield above -->
+    <symbol id="g-pulse" viewBox="0 0 24 24">
+      <path fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" d="M3 12h4l3-7 4 14 3-7h4"/>
+    </symbol>
     <symbol id="g-lifebuoy" viewBox="0 0 24 24">
       <g fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round">
         <circle cx="12" cy="12" r="8.6"/><circle cx="12" cy="12" r="3.6"/>
@@ -165,6 +170,41 @@
     </symbol>
 </svg>
 
+  <!-- ═══ BOOT SPLASH ═══ covers the shell while the first data loads;
+       dashboard.js lifts it once the welcome cards are rendered -->
+  <div id="app-splash" role="status" aria-live="polite">
+    <div class="splash-card">
+      <div class="splash-ring">
+        <img src="/static/sovran-hub-icon.svg" alt="" width="64" height="64" />
+        <span class="splash-ring-arc" aria-hidden="true"></span>
+      </div>
+      <div class="splash-title">Starting The Hub</div>
+      <div class="splash-sub" id="splash-sub">Gathering your services…</div>
+    </div>
+  </div>
+  <script>
+    (function () {
+      var splash = document.getElementById("app-splash");
+      var sub = document.getElementById("splash-sub");
+      var lifted = false;
+      function lift() {
+        if (lifted || !splash) return;
+        lifted = true;
+        splash.classList.add("done");
+        setTimeout(function () {
+          if (splash && splash.parentNode) splash.parentNode.removeChild(splash);
+        }, 500);
+      }
+      window.__liftAppSplash = lift;
+      // Reassure the user if the backend is slow (e.g. right after a reboot)
+      setTimeout(function () {
+        if (!lifted && sub) sub.textContent = "Still starting\u2026 this can take a moment after a reboot.";
+      }, 8000);
+      // Never trap the user behind the splash
+      setTimeout(lift, 25000);
+    })();
+  </script>
+
   <div class="app">
 
     <!-- ═══ SIDEBAR ═══ -->
@@ -250,7 +290,7 @@
     <div class="creds-dialog">
       <div class="creds-header">
         <span class="creds-title" id="systems-modal-title">
-          <span class="widget-chip chip-green" style="width:54px;height:54px;border-radius:16px"><svg style="width:27px;height:27px"><use href="#g-shield-check"/></svg></span>
+          <span class="widget-chip chip-green" style="width:54px;height:54px;border-radius:16px"><svg style="width:27px;height:27px"><use href="#g-pulse"/></svg></span>
           <span>Systems Operational</span>
         </span>
         <button class="creds-close-btn" id="systems-close-btn" title="Close">✕</button>
@@ -317,7 +357,10 @@
   <div class="modal-overlay" id="support-modal" role="dialog" aria-modal="true" aria-labelledby="support-modal-title">
     <div class="creds-dialog">
       <div class="creds-header">
-        <span class="creds-title" id="support-modal-title">Tech Support</span>
+        <span class="creds-title">
+          <span class="widget-chip chip-neutral" id="support-modal-chip" style="width:54px;height:54px;border-radius:16px"><svg style="width:27px;height:27px"><use href="#g-lifebuoy"/></svg></span>
+          <span id="support-modal-title">Tech Support</span>
+        </span>
         <button class="creds-close-btn" id="support-close-btn" title="Close">✕</button>
       </div>
       <div class="creds-body" id="support-body">