Fase 2: read-only user role with per-category view toggles

Adds a third account type 'user' alongside super/admin: no create/edit/delete
rights on qr codes, view access to dynamic/static lists gated per-account by
two admin-controlled toggles (can_view_static, can_view_dynamic), and always
full visibility into the dashboard/reports regardless of those toggles.

- New columns can_view_static/can_view_dynamic on users (migrations/003)
- Users class + form_users.php: 'user' type option with the two toggles
- Access control: dynamic_qrcode.php/static_qrcode.php/bulk_action.php reject
  all mutations for type=user; dynamic_qrcodes.php/static_qrcodes.php enforce
  the view toggle and show all codes (no owner scoping, since 'user' owns none)
- Sidebar and list tables hide add/edit/delete/bulk UI for the read-only role
- index.php dashboard stats are unscoped for both 'super' and 'user'

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/forms/table_dynamic.php

@@ -1,4 +1,6 @@
+<?php $is_readonly_user = $_SESSION['type'] === 'user'; ?>
 <div class="row">
+    <?php if (!$is_readonly_user): ?>
     <div class="col-12" id="bulk-action-div" style="display: none;">
         <div id="err-msg"></div>
         <div class="bulk-action-wrapper">
@@ -21,13 +23,16 @@
             </form>
         </div>
     </div>
+    <?php endif; ?>
     <div class="col-12">
         <div class="card">
             <div class="card-body table-responsive p-0">
       <table class="table table-striped table-bordered">
         <thead>
             <tr>
+                <?php if (!$is_readonly_user): ?>
                 <th><input type="checkbox" name="bulk-select" value="1"></th>
+                <?php endif; ?>
                 <th>ID</th>
                 <th>Owner</th>
                 <th>Filename</th>
@@ -42,7 +47,9 @@
         <tbody>
             <?php foreach ($rows as $row): ?>
             <tr>
+                <?php if (!$is_readonly_user): ?>
                 <td><input type="checkbox" name="action[]" value="<?=$row['id']?>" onchange="updateBulkActionVisibility()"></td>
+                <?php endif; ?>
                 <td><?php echo $row['id']; ?></td>
                 <td>
                     <?php
@@ -68,10 +75,10 @@
                 <td><?php echo htmlspecialchars($row['scan']); ?></td>
                 <td><?php echo htmlspecialchars($row['state']); ?></td>
                 <td>
-                    
+                    <?php if (!$is_readonly_user): ?>
                     <!-- EDIT -->
                     <a href="dynamic_qrcode.php?edit=true&id=<?php echo $row['id']; ?>" class="btn btn-primary"><i class="fas fa-edit"></i></a>
-                    
+
                     <!-- DELETE -->
                     <a
                             class="btn btn-danger delete_btn"
@@ -79,7 +86,7 @@
                             data-target="#delete-modal"
                             data-del_id="<?php echo $row["id"];?>"
                     ><i class="fas fa-trash"></i></a>
-                    
+                    <?php endif; ?>
                     <!-- DOWNLOAD -->
                     <a href="<?php echo SAVED_QRCODE_FOLDER.htmlspecialchars($row['qrcode']); ?>" class="btn btn-primary" download><i class="fa fa-download"></i></a>
                 </td>
@@ -97,6 +104,7 @@
     </div><!-- /.col -->
 </div><!-- /.row -->
 
+<?php if (!$is_readonly_user): ?>
 <!-- Delete Confirmation Modal -->
 <div class="modal fade" id="delete-modal" role="dialog">
     <div class="modal-dialog">
@@ -122,6 +130,7 @@
     </div>
 </div>
 <!-- /.Delete Confirmation Modal -->
+<?php endif; ?>
 
 <script>
     const deleteButtons = document.querySelectorAll('.delete_btn');