feat(ansible): cross-link inventory/schedules/browse for discoverability

The inventory CRUD UI (/ansible/inventory/targets + /groups) existed but was
unreachable from the main Ansible pages — only a buried text hint pointed to
it. Add an "Inventory" button to the Runs, Browse, and Schedules headers, and
"← Ansible" back-links on the inventory target/group pages, so the targeting
features (manual runs, schedules, Deploy-via-Ansible) are findable.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

steward/templates/ansible/inventory/groups.html

@@ -3,7 +3,10 @@
 {% block content %}
 <div style="display:flex;align-items:center;justify-content:space-between;margin-bottom:1.5rem;">
     <h1 class="page-title" style="margin-bottom:0;">Inventory Groups</h1>
-    <a href="/ansible/inventory/targets" class="btn btn-ghost btn-sm">Targets →</a>
+    <div style="display:flex;gap:0.5rem;">
+        <a href="/ansible/inventory/targets" class="btn btn-ghost btn-sm">Targets</a>
+        <a href="/ansible/" class="btn btn-ghost btn-sm">← Ansible</a>
+    </div>
 </div>
 
 <div class="card" style="margin-bottom:1.5rem;">