fix(ui): Integrate webhooks panel into status panel

The webhooks panel was appearing separately from the status panel.
Now it's properly nested inside the status-panel div:

- Moved webhooks-section inside status-panel in HTML
- Updated CSS so nested webhooks looks like a subsection (no double borders)
- Simplified JS toggle logic - webhooks shows/hides automatically with status panel
- Admin users see webhooks inside status panel, collapsed by default

public/index.html

@@ -68,10 +68,9 @@
                 </div>
             </header>
 
-            <div id="status-panel" class="status-panel" style="display: none;"></div>
-
-            <!-- Webhooks Configuration Panel (inline with status) -->
-            <div class="webhooks-section" id="webhooks-section" style="display: none;">
+            <div id="status-panel" class="status-panel" style="display: none;">
+                <!-- Webhooks Configuration Panel (nested inside status) -->
+                <div class="webhooks-section" id="webhooks-section" style="display: none;">
                 <div class="webhooks-header" id="webhooks-header">
                     <h2>⚡ Webhooks Configuration</h2>
                     <span class="webhooks-toggle" id="webhooks-toggle">▼</span>
@@ -128,6 +127,7 @@
                     </div>
                 </div>
             </div>
+            </div>
 
             <div id="error-message" class="error-message" style="display: none;"></div>