new: add password visibility toggle on all password fields

Reusable ``password_toggle.blade.php`` partial that wraps every
``input[type=password]`` with an eye icon button. Clicking it
toggles between hidden and visible text. Handles Bootstrap modals
via ``shown.bs.modal`` event. Applied on login, register, password
change (shop + admin), password reset, and first login pages.

resources/views/Shop/auth/partials/login.blade.php

@@ -15,9 +15,9 @@
     <div class="input-group form-group {{ $errors->has('password') ? 'has-error' : '' }}">
         {{ Form::password('password', ['class' => 'form-control', 'placeholder' => __('boilerplate::auth.fields.password'), 'required']) }}
         <div class="input-group-append">
-            <div class="btn btn-outline-secondary">
-                <i class="fa fa-lock"></i>
-            </div>
+            <button class="btn btn-outline-secondary password-toggle" type="button" tabindex="-1">
+                <i class="fa fa-eye"></i>
+            </button>
         </div>
     </div>
     {!! $errors->first('password', '<p class="text-danger"><strong>:message</strong></p>') !!}
@@ -46,4 +46,5 @@
             -->
     </div>
 </div>
+@include('load.form.password_toggle')
 {!! Form::close() !!}