a11y: WCAG 2.5.5 target sizes + 2.5.3 label-in-name fixes

Increase touch/click target sizes to meet WCAG 2.5.5 (minimum 44×44px
for navigation, 32px for admin UI controls):

- main.css / search.css: pagination buttons 2rem → min-height/min-width
  2.75rem (44px). Changed display to inline-flex for proper centering.
- admin.css: .admin-btn-sm gains min-height: 2rem (32px) and switches
  to inline-flex so the constraint is respected.
- admin.css: .admin-btn-remove (jury ✕ buttons) gains min-height: 2rem
  and inline-flex display + explicit cursor:pointer.

WCAG 2.5.3 label-in-name — jury remove buttons already had aria-label;
wrap the visible ✕ glyph in <span aria-hidden='true'> so screen readers
hear only the aria-label, not the symbol:

- templates/partials/form/jury-fieldset.php: all three ✕ occurrences
  (static PHP blocks + JS-generated innerHTML string) wrapped.

WCAG 4.1.2 / semantic HTML:
- admin/index.php: add role='toolbar' aria-label='Actions groupées' to
  the bulk-actions bar.

public/assets/css/admin.css

@@ -378,12 +378,14 @@
 
 .admin-btn-sm {
   padding: 0.25rem 0.6rem;
+  min-height: 2rem;    /* WCAG 2.5.5: ≥32px touch target */
   border-radius: 3px;
   font-size: 0.78rem;
   font-family: inherit;
   cursor: pointer;
   text-decoration: none;
-  display: inline-block;
+  display: inline-flex;
+  align-items: center;
   border: 1px solid transparent;
   transition: all 0.15s;
   white-space: nowrap;
@@ -591,9 +593,13 @@
     border: 1px solid var(--border-primary);
     color: #969696;
     border-radius: 3px;
-    padding: 0.2rem 0.45rem;
+    padding: 0.2rem 0.55rem;
+    min-height: 2rem;    /* WCAG 2.5.5: ≥32px touch target */
     font-size: 0.8rem;
     line-height: 1;
+    display: inline-flex;
+    align-items: center;
+    cursor: pointer;
   }
   .admin-btn-remove:hover {
     border-color: #e55;

public/assets/css/main.css

@@ -193,9 +193,9 @@
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  min-width: 2rem;
-  height: 2rem;
-  padding: 0 0.5rem;
+  min-width: 2.75rem;
+  min-height: 2.75rem;
+  padding: 0 0.6rem;
   border: 1px solid var(--border-secondary);
   border-radius: 3px;
   color: var(--text-primary);

public/assets/css/search.css

@@ -269,9 +269,9 @@
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  min-width: 2rem;
-  height: 2rem;
-  padding: 0 0.5rem;
+  min-width: 2.75rem;
+  min-height: 2.75rem;
+  padding: 0 0.6rem;
   border: 1px solid var(--border-secondary);
   border-radius: 3px;
   color: var(--text-primary);