Add multi-boot PXE menu, Clonezilla backup management, and GE Aerospace branding

- iPXE boot menu with WinPE, Clonezilla, Blancco Drive Eraser, Memtest86+
- prepare-boot-tools.sh to download/extract boot tool binaries
- Clonezilla backup management in webapp (upload, download, delete)
- Clonezilla Samba share for network backup/restore
- GE Aerospace logo and favicon in webapp
- Updated playbook with boot tool directories and webapp env vars

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

webapp/templates/base.html

@@ -4,6 +4,7 @@
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>{% block title %}PXE Server Manager{% endblock %}</title>
+  <link rel="icon" href="{{ url_for('static', filename='favicon.ico') }}" type="image/x-icon">
   <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css"
         rel="stylesheet"
         integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YcnS49cn91B2HOwP4cMpe1bBMnos9GBsYl7a"
@@ -115,7 +116,7 @@
   <!-- Sidebar -->
   <nav class="sidebar d-flex flex-column">
     <div class="brand">
-      <i class="bi bi-hdd-network"></i>
+      <img src="{{ url_for('static', filename='ge-aerospace-logo.svg') }}" alt="GE Aerospace" style="height: 28px; filter: brightness(0) invert(1);">
       PXE Manager
     </div>
     <ul class="nav flex-column mt-2">
@@ -134,9 +135,20 @@
     </ul>
 
     <div class="nav-section-divider"></div>
-    <div class="sidebar-heading">PBR Images</div>
+    <div class="sidebar-heading">Tools</div>
     <ul class="nav flex-column">
-      {% for it in ['geastandardpbr', 'geaengineerpbr', 'geashopfloorpbr'] %}
+      <li class="nav-item">
+        <a class="nav-link {% if request.endpoint == 'clonezilla_backups' %}active{% endif %}"
+           href="{{ url_for('clonezilla_backups') }}">
+          <i class="bi bi-archive"></i> Clonezilla Backups
+        </a>
+      </li>
+    </ul>
+
+    <div class="nav-section-divider"></div>
+    <div class="sidebar-heading">GE Aerospace Images</div>
+    <ul class="nav flex-column">
+      {% for it in ['gea-standard', 'gea-engineer', 'gea-shopfloor'] %}
       <li class="nav-item">
         <a class="nav-link {% if request.endpoint == 'unattend_editor' and image_type is defined and image_type == it %}active{% endif %}"
            href="{{ url_for('unattend_editor', image_type=it) }}">
@@ -147,9 +159,9 @@
     </ul>
 
     <div class="nav-section-divider"></div>
-    <div class="sidebar-heading">Legacy Images</div>
+    <div class="sidebar-heading">GE Legacy Images</div>
     <ul class="nav flex-column">
-      {% for it in ['gestandardlegacy', 'geengineerlegacy', 'geshopfloorlegacy'] %}
+      {% for it in ['ge-standard', 'ge-engineer', 'ge-shopfloor-lockdown', 'ge-shopfloor-mce'] %}
       <li class="nav-item">
         <a class="nav-link {% if request.endpoint == 'unattend_editor' and image_type is defined and image_type == it %}active{% endif %}"
            href="{{ url_for('unattend_editor', image_type=it) }}">