feat: add ntfy access token support

- ntfy push notifications now include a Bearer access token when configured
- Add Access Token field to /admin/settings next to server and topic
- Token is stored encrypted like the SMTP password
- Bump version to 0.5.7

templates/admin/settings.html

@@ -308,6 +308,13 @@
               <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>
+            <tr>
+              <td>ntfy Access Token</td>
+              <td>
+                <input type="password" id="ntfy_token" name="ntfy_token" placeholder="{% if ntfy.get('ntfy_token') %}Stored encrypted — type to replace{% else %}Enter token (optional){% endif %}">
+                <p class="copy-hint">Required if the topic is access-controlled. Leave blank to keep the existing stored token.</p>
+              </td>
+            </tr>
           </table>
           <button type="submit">Save ntfy Settings</button>
         </form>