feat: add ntfy push notifications for new requests

- Add ntfy server/topic settings in /admin/settings next to Hermes API key
- POST a push notification to the configured topic on every new customer request
- Add a Send Test ntfy button to verify configuration
- Add requests dependency for ntfy HTTP calls
- Bump version to 0.5.6

templates/admin/settings.html

@@ -293,6 +293,34 @@
         {% endif %}
       </div>
 
+      <!-- ntfy push notifications -->
+      <div class="section">
+        <h2>ntfy Notifications</h2>
+        <p class="copy-hint">Push notifications for new customer requests. Leave either field blank to disable.</p>
+        <form method="POST">
+          <input type="hidden" name="action" value="save_ntfy">
+          <table class="meta-table">
+            <tr>
+              <td>ntfy Server URL</td>
+              <td><input type="text" id="ntfy_server" name="ntfy_server" value="{{ ntfy.get('ntfy_server', '') }}" placeholder="e.g. https://ntfy.hallsworth.ca"></td>
+            </tr>
+            <tr>
+              <td>ntfy Topic</td>
+              <td><input type="text" id="ntfy_topic" name="ntfy_topic" value="{{ ntfy.get('ntfy_topic', '') }}" placeholder="e.g. Troll-AI-ntfy"></td>
+            </tr>
+          </table>
+          <button type="submit">Save ntfy Settings</button>
+        </form>
+
+        <hr style="border:none;border-top:1px solid var(--border);margin:1.5rem 0;">
+
+        <h3>Send Test Notification</h3>
+        <form method="POST">
+          <input type="hidden" name="action" value="send_test_ntfy">
+          <button type="submit">Send Test ntfy</button>
+        </form>
+      </div>
+
       <!-- Email / SMTP configuration -->
       <div class="section">
         <h2>Email (SMTP) Settings</h2>