refactor: combined duration (pages + minutes), has_annexes checkbox, remove Mo

- Remove Mo option from duration, keep only pages and minutes
- Redesign duration fieldset: separate Pages input + Durée h:m inputs, both can be set together
- Fix minutes input visibility: wider inputs (6ch), proper CSS layout
- Add has_annexes checkbox to fichiers fragment + DB column + controllers
- Display duration on admin backoffice recap page
- Display duration on public partage recap page
- Update public TFE page for new combined duration format
- Migration 041: add duration_pages, duration_minutes, has_annexes columns; migrate data; recreate views

app/public/assets/css/admin.css

@@ -2160,18 +2160,36 @@ th.admin-ap-col {
   100% { transform: scaleX(0);   transform-origin: right; }
 }
 
-/* ── Sidebar TOC (matches public .page-content alignment pattern) ────────── */
+/* ── Sidebar TOC (matches public .page-content grid layout) ────────────── */
 
 .admin-main--toc {
-    display: flex;
+    display: grid;
+    grid-template-columns: 180px 1fr;
     gap: var(--space-2xl);
     align-items: start;
     padding: var(--space-xl) var(--space-m) var(--space-2xl);
 }
 
-.admin-main--toc > article {
-    flex: 1;
-    min-width: 0;
+/* Desktop: article in second column */
+@media (min-width: 768px) {
+    .admin-main--toc > article {
+        grid-column: 2;
+        min-width: 0;
+        max-width: 100%;
+    }
+}
+
+/* Mobile: single column */
+@media (max-width: 767px) {
+    .admin-main--toc {
+        grid-template-columns: 1fr;
+        gap: var(--space-l);
+        padding: var(--space-m) var(--space-s) var(--space-xl);
+    }
+
+    .admin-main--toc > article {
+        grid-column: 1;
+    }
 }
 
 /* Align first child of article with TOC heading (same as public) */
@@ -2188,11 +2206,6 @@ th.admin-ap-col {
 }
 
 /* Admin TOC: same <details class="toc"> as public pages, positioned sticky */
-#admin-toc {
-    width: 180px;
-    flex-shrink: 0;
-}
-
 #admin-toc .toc-list a {
     font-size: var(--step--1);
 }