feat(BlockEditor): auto-open link popover when clicking on existing link

- add `linkRangeAt` import to detect link span under caret
- handle `mouseup` on container to detect collapsed click inside a link mark
- set `autoOpenLink` flag via ref and expand selection to full link range
- pass `autoOpenLink` to toolbar state and use `initialPopover='link'` prop
- initialize toolbar popover state from `initialPopover` prop
- pre-fill link url and new-tab from existing mark when `initialPopover` is set
- add `linkRangeAt` helper in `types.js` to find enclosing link range at offset

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

@@ -23,12 +23,13 @@ const SIMPLE_BUTTONS = [
   { type: 'code', label: <CodeSimpleIcon width={15} height={15} />, title: 'Code (Ctrl+E)', className: '' },
 ];
 
-export default function InlineToolbar({ rect, activeMarks, onToggleMark, onSetMark, onClearMarks, onPinChange, usedColors }) {
+export default function InlineToolbar({ rect, activeMarks, onToggleMark, onSetMark, onClearMarks, onPinChange, usedColors, initialPopover }) {
   const ref = useRef(null);
   const [pos, setPos] = useState({ top: 0, left: 0, flipped: false });
-  const [popover, setPopover] = useState(null); // 'color' | 'highlight' | 'link' | null
-  const [linkUrl, setLinkUrl] = useState('');
-  const [linkNewTab, setLinkNewTab] = useState(false);
+  const [popover, setPopover] = useState(initialPopover ?? null);
+  const existingLink = initialPopover === 'link' ? activeMarks?.find(m => m.type === 'link') : null;
+  const [linkUrl, setLinkUrl] = useState(existingLink?.href ?? '');
+  const [linkNewTab, setLinkNewTab] = useState(existingLink ? !!existingLink.newTab : false);
 
   useEffect(() => {
     onPinChange?.(popover !== null);

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

@@ -205,6 +205,33 @@ export function marksAtOffset(nodes, offset) {
   return last.marks ? last.marks.map(m => ({ ...m })) : [];
 }
 
+// Trouve le début et la fin continus du span qui porte un lien à `offset`.
+// Retourne { start, end, mark } ou null si aucun lien à cet offset.
+export function linkRangeAt(nodes, offset) {
+  if (!Array.isArray(nodes) || nodes.length === 0) return null;
+  const marks = marksAtOffset(nodes, offset);
+  const linkMark = marks.find(m => m.type === 'link');
+  if (!linkMark) return null;
+  const key = markKey(linkMark);
+  let pos = 0;
+  let start = null;
+  let end = null;
+  for (const node of nodes) {
+    const len = node.text?.length ?? 0;
+    const nodeEnd = pos + len;
+    const hasLink = (node.marks ?? []).some(m => markKey(m) === key);
+    if (hasLink) {
+      if (start === null) start = pos;
+      end = nodeEnd;
+    } else if (start !== null) {
+      break;
+    }
+    pos = nodeEnd;
+  }
+  if (start === null) return null;
+  return { start, end, mark: linkMark };
+}
+
 // Marks communes à toute la plage [start, end[. Si la plage est vide,
 // retourne les marks à l'offset `start`. Utile pour afficher l'état actif
 // du toolbar.