feat(BlockEditor): add setMark utility and wire link submission to it

- add `setMark` helper in `types.js` that removes then applies a mark, replacing existing marks of the same type without toggling
- expose `applySetMark` in `BlockEditor.client.js` and pass it as `onSetMark` prop to `InlineToolbar`
- switch `handleLinkSubmit` in `Toolbar.client.js` to use `onSetMark` instead of `onToggleMark` so re-submitting a link always applies the new href

src/shared/components/BlockEditor/inline/Toolbar.client.js

@@ -23,7 +23,7 @@ const SIMPLE_BUTTONS = [
   { type: 'code', label: <CodeSimpleIcon width={15} height={15} />, title: 'Code (Ctrl+E)', className: '' },
 ];
 
-export default function InlineToolbar({ rect, activeMarks, onToggleMark, onClearMarks, onPinChange, usedColors }) {
+export default function InlineToolbar({ rect, activeMarks, onToggleMark, onSetMark, onClearMarks, onPinChange, usedColors }) {
   const ref = useRef(null);
   const [pos, setPos] = useState({ top: 0, left: 0, flipped: false });
   const [popover, setPopover] = useState(null); // 'color' | 'highlight' | 'link' | null
@@ -75,9 +75,9 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onClear
   }
 
   function handleLinkSubmit(e) {
-    e.preventDefault();
+    e.preventDefault?.();
     if (!linkUrl) return;
-    onToggleMark?.({ type: 'link', href: linkUrl, newTab: linkNewTab });
+    onSetMark?.({ type: 'link', href: linkUrl, newTab: linkNewTab });
     setLinkUrl('');
     setPopover(null);
   }

src/shared/components/BlockEditor/inline/types.js

@@ -304,6 +304,13 @@ export function removeMark(nodes, start, end, type) {
   return mapRange(nodes, start, end, n => removeMarkFromNode(n, type));
 }
 
+// Retire le type existant et applique la nouvelle mark — utile pour remplacer
+// un lien sans passer par le toggle (qui retirerait si même href).
+export function setMark(nodes, start, end, mark) {
+  const removed = removeMark(nodes, start, end, mark.type);
+  return applyMark(removed, start, end, mark);
+}
+
 // Toggle : si toute la plage porte déjà la mark (au sens markKey strict),
 // on la retire ; sinon on l'applique partout.
 export function toggleMark(nodes, start, end, mark) {