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)

public/assets/css/admin.css

@@ -47,7 +47,7 @@
   gap: 0;
 }
 
-.admin-form > div:not(.admin-submit-wrap) {
+.admin-form > div:not(.admin-form-footer) {
   display: grid;
   grid-template-columns: 260px 1fr;
   align-items: start;
@@ -56,12 +56,12 @@
   gap: 1rem;
 }
 
-.admin-form > div:not(.admin-submit-wrap):last-of-type {
+.admin-form > div:not(.admin-form-footer):last-of-type {
   border-bottom: 1px solid var(--border-primary);
 }
 
-.admin-form > div:not(.admin-submit-wrap) > label,
-.admin-form > div:not(.admin-submit-wrap) > span.admin-row-label {
+.admin-form > div:not(.admin-form-footer) > label,
+.admin-form > div:not(.admin-form-footer) > span.admin-row-label {
   font-size: 0.92rem;
   padding-top: 0.5rem;
   font-weight: 400;
@@ -204,7 +204,7 @@
 }
 
 /* ── Buttons ────────────────────────────────────────────────────────────── */
-.admin-submit-wrap {
+.admin-form-footer {
   margin-top: 2rem;
   padding-top: 1.5rem;
 }
@@ -718,19 +718,19 @@
   text-align: center;
 }
 
-.admin-login-box .admin-form > div:not(.admin-submit-wrap) {
+.admin-login-box .admin-form > div:not(.admin-form-footer) {
   grid-template-columns: 1fr;
   border: none;
   padding: 0.4rem 0;
 }
 
-.admin-login-box .admin-form > div:not(.admin-submit-wrap) > label {
+.admin-login-box .admin-form > div:not(.admin-form-footer) > label {
   font-size: 0.82rem;
   color: var(--text-secondary);
   margin-bottom: 0.2rem;
 }
 
-.admin-login-box .admin-submit-wrap {
+.admin-login-box .admin-form-footer {
   margin-top: 1rem;
   padding-top: 0.5rem;
 }