fix(ui): move onMouseDown prevention to individual toolbar buttons and default linkNewTab to false

- move `e.preventDefault()` from toolbar container to each individual button to avoid broad focus prevention
- default `linkNewTab` state to `false` instead of `true` for new links
- add `onMouseDown` prevention to color grid buttons

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

@@ -27,7 +27,7 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onPinCh
   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(true);
+  const [linkNewTab, setLinkNewTab] = useState(false);
 
   useEffect(() => {
     onPinChange?.(popover !== null);
@@ -91,7 +91,7 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onPinCh
   function openLinkPopover() {
     const link = activeMarks.find(m => m.type === 'link');
     setLinkUrl(link?.href ?? '');
-    setLinkNewTab(link ? !!link.newTab : true);
+    setLinkNewTab(link ? !!link.newTab : false);
     setPopover(p => (p === 'link' ? null : 'link'));
   }
 
@@ -101,13 +101,13 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onPinCh
       data-inline-toolbar
       className="fixed z-50 flex items-center gap-0.5 rounded-lg border border-neutral-200 dark:border-neutral-700 bg-white dark:bg-neutral-900 shadow-md px-1 py-1"
       style={{ top: pos.top, left: pos.left }}
-      onMouseDown={(e) => e.preventDefault()}
     >
       {SIMPLE_BUTTONS.map(btn => (
         <button
           key={btn.type}
           type="button"
           title={btn.title}
+          onMouseDown={(e) => e.preventDefault()}
           onClick={() => handleSimple(btn.type)}
           className={`w-7 h-7 flex items-center justify-center rounded text-sm text-neutral-700 dark:text-neutral-300 hover:bg-neutral-100 dark:hover:bg-neutral-800 ${btn.className} ${isActive(btn.type) ? 'bg-neutral-100 dark:bg-neutral-800' : ''}`}
         >
@@ -120,6 +120,7 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onPinCh
       <button
         type="button"
         title="Couleur du texte"
+        onMouseDown={(e) => e.preventDefault()}
         onClick={() => setPopover(p => (p === 'color' ? null : 'color'))}
         className={`w-7 h-7 flex items-center justify-center rounded text-sm text-neutral-700 dark:text-neutral-300 hover:bg-neutral-100 dark:hover:bg-neutral-800 ${isActive('color') ? 'bg-neutral-100 dark:bg-neutral-800' : ''}`}
       >
@@ -128,6 +129,7 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onPinCh
       <button
         type="button"
         title="Surlignage"
+        onMouseDown={(e) => e.preventDefault()}
         onClick={() => setPopover(p => (p === 'highlight' ? null : 'highlight'))}
         className={`w-7 h-7 flex items-center justify-center rounded text-sm text-neutral-700 dark:text-neutral-300 hover:bg-neutral-100 dark:hover:bg-neutral-800 ${isActive('highlight') ? 'bg-neutral-100 dark:bg-neutral-800' : ''}`}
       >
@@ -136,6 +138,7 @@ export default function InlineToolbar({ rect, activeMarks, onToggleMark, onPinCh
       <button
         type="button"
         title="Lien (Ctrl+K)"
+        onMouseDown={(e) => e.preventDefault()}
         onClick={openLinkPopover}
         className={`w-7 h-7 flex items-center justify-center rounded text-sm text-neutral-700 dark:text-neutral-300 hover:bg-neutral-100 dark:hover:bg-neutral-800 ${isActive('link') ? 'bg-neutral-100 dark:bg-neutral-800' : ''}`}
       >
@@ -213,6 +216,7 @@ function ColorGrid({ mode, activeKey, onPick }) {
             key={key}
             type="button"
             title={key}
+            onMouseDown={(e) => e.preventDefault()}
             onClick={() => onPick(key)}
             className={`w-6 h-6 flex items-center justify-center rounded ${tw} ${activeKey === key ? 'ring-2 ring-blue-500' : ''}`}
           >