rename admin-submit-wrap → admin-form-footer across all templates and CSS

- Updated 6 admin templates: add.php, edit.php, login.php, account.php,
  import.php, pages-edit.php — replaced <div class="admin-submit-wrap">
  with <div class="admin-form-footer">
- Updated 8 CSS selectors in admin.css:
  - .admin-form-footer { margin-top/padding-top } (was .admin-submit-wrap)
  - .admin-form > div:not(.admin-form-footer) grid exclusion guard (×3)
  - .admin-login-box .admin-form > div:not(.admin-form-footer) overrides (×2)
  - .admin-login-box .admin-form-footer compact spacing override
- No visual change; purely a semantic rename to a descriptive class name
- Also marked status-badge.php partial and WCAG 1.3.1 badge tasks as
  already-done in todo/02-php-components.md and todo/04-accessibility.md
  (partial + CSS were fully implemented but todo had not been updated)

todo/04-accessibility.md

@@ -8,7 +8,7 @@
 
 - [x] **Admin form rows: multi-input rows (languages, formats)** — `checkbox-list.php` partial now wraps checkboxes in `<fieldset class="admin-checkbox-group">` with a `<legend class="sr-only">` for AT grouping
 
-- [ ] **Status badges in `admin/index.php` convey state by colour alone** — add visible non-colour distinction (prefix icon with `aria-hidden="true"`) and `aria-label="Statut : Publié"` on badge `<span>`
+- [x] **Status badges in `admin/index.php` convey state by colour alone** — `status-badge.php` partial emits `<span aria-label="Statut : Publié"><span aria-hidden="true">● </span>Publié</span>` (circle symbol is non-colour indicator); both publish and access badges implemented
 
 ## 1.3.4 / 1.3.5 Orientation & Input purpose