Fix email logo: resize/compress to small JPEG, make path configurable in settings, add Pillow

templates/admin/settings.html

@@ -263,6 +263,10 @@
                 <input type="password" id="smtp_pass" name="smtp_pass" placeholder="{% if email_form.smtp_pass_set %}Stored encrypted — type to replace{% else %}Enter password{% endif %}">
               </td>
             </tr>
+            <tr>
+              <td>Logo Path</td>
+              <td><input type="text" id="logo_path" name="logo_path" value="{{ email_form.logo_path }}" placeholder="e.g. /mnt/Storage/DM-Logo.png"></td>
+            </tr>
           </table>
           <button type="submit">Save Email Settings</button>
         </form>