Add tiled homepage; rename Business→Businesses; link footer copyright

- Home page (home.html) at / shows the sidebar sections as tiles; reachable by
  clicking the 'SimpleX Manager' brand in the sidebar (was redirecting to /users).
- Rename the category to 'Businesses' (route /businesses, tab/nav/_category),
  keeping the per-account bot_type 'business'. Fix profile back-link label.
- Footer: link 'Bournemouth Technology Ltd' -> bournemouthtechnology.co.uk and
  'SimpleX Network' -> simplex.chat.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

manager/templates/base.html

@@ -264,12 +264,12 @@
 <button class="mobile-menu-btn" onclick="toggleSidebar()" aria-label="Menu">☰</button>
 <div class="app">
   <aside class="sidebar" id="sidebar">
-    <a class="nav-brand" href="/users">
+    <a class="nav-brand" href="/">
       <span class="brand-icon">◆</span><span class="brand-text">SimpleX Manager</span>
     </a>
     <nav class="side-nav">
       <a href="/users"    {% if nav_active == 'users'    %}class="active"{% endif %}><span class="ico">👤</span><span class="lbl">Users</span></a>
-      <a href="/business" {% if nav_active == 'business' %}class="active"{% endif %}><span class="ico">💼</span><span class="lbl">Business</span></a>
+      <a href="/businesses" {% if nav_active == 'businesses' %}class="active"{% endif %}><span class="ico">💼</span><span class="lbl">Businesses</span></a>
       <a href="/bots"     {% if nav_active == 'bots'     %}class="active"{% endif %}><span class="ico">🤖</span><span class="lbl">Bots</span></a>
       <a href="https://simplex.chat/file/" target="_blank" rel="noopener"><span class="ico">📁</span><span class="lbl">File upload</span></a>
       <a href="/notifications" class="nav-sep {% if nav_active == 'notifications' %}active{% endif %}"><span class="ico">🔔</span><span class="lbl">Notifications</span><span class="notif-badge" id="notif-badge" style="display:none;"></span></a>
@@ -297,9 +297,9 @@
       {% block content %}{% endblock %}
     </div>
     <footer class="site-footer">
-      © Bournemouth Technology Ltd
+      © <a href="https://bournemouthtechnology.co.uk" target="_blank" rel="noopener">Bournemouth Technology Ltd</a>
       <span class="sep">·</span>
-      built on © SimpleX Network
+      built on © <a href="https://simplex.chat" target="_blank" rel="noopener">SimpleX Network</a>
       <span class="sep">·</span>
       <a href="https://simplex.chat/downloads/" target="_blank" rel="noopener">Get SimpleX App</a>
     </footer>