fix(BlockEditor): close slash menu when clicking outside or on different block

- add `handleFocus` in Block to reopen slash menu on focus if content starts with `/`
- add `outerRef` on editor root div to detect outside clicks
- add `useEffect` with document `mousedown` listener to close slash menu when clicking outside the editor or on a different block
- add `data-slash-menu` attribute on SlashMenu to exclude it from the close trigger

src/shared/components/BlockEditor/Block.client.js

@@ -205,6 +205,17 @@ const Block = forwardRef(function Block(
     }
   }
 
+  function handleFocus() {
+    if (def?.isText && !disabled) {
+      const el = editableRef.current;
+      const text = el?.textContent ?? '';
+      if (text.startsWith('/') && !text.slice(1).includes(' ')) {
+        onSlashOpen?.({ blockId: block.id, query: text.slice(1) });
+      }
+    }
+    onFocus?.(block.id);
+  }
+
   function handlePaste(e) {
     // MVP : on colle uniquement du texte brut pour éviter le HTML externe.
     e.preventDefault();
@@ -324,7 +335,7 @@ const Block = forwardRef(function Block(
                 onInput={handleInput}
                 onKeyDown={handleKeyDown}
                 onPaste={handlePaste}
-                onFocus={() => onFocus?.(block.id)}
+                onFocus={handleFocus}
               />
             </div>
           ) : (
@@ -336,7 +347,7 @@ const Block = forwardRef(function Block(
               onInput={handleInput}
               onKeyDown={handleKeyDown}
               onPaste={handlePaste}
-              onFocus={() => onFocus?.(block.id)}
+              onFocus={handleFocus}
             />
           )
         ) : def.Component ? (

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

@@ -71,6 +71,7 @@ export default function BlockEditor({
   const blocks = useMemo(() => ensureNonEmpty(value), [value]);
   const blockRefs = useRef(new Map());
   const containerRef = useRef(null);
+  const outerRef = useRef(null);
   const [focusBlockId, setFocusBlockId] = useState(null);
   const [focusOffset, setFocusOffset] = useState(null);
   const [selectedBlockIds, setSelectedBlockIds] = useState(() => new Set());
@@ -764,6 +765,26 @@ export default function BlockEditor({
     selectAllBlocks();
   }
 
+  // Ferme le slash menu quand on clique en dehors de l'éditeur ou sur un
+  // bloc différent de celui qui a ouvert le menu.
+  useEffect(() => {
+    if (!slashState) return;
+    function onDocMouseDown(e) {
+      if (e.target instanceof Element && e.target.closest('[data-slash-menu]')) return;
+      const outer = outerRef.current;
+      if (!outer || !outer.contains(e.target)) {
+        setSlashState(null);
+        return;
+      }
+      const blockEl = e.target instanceof Element ? e.target.closest('[data-block-id]') : null;
+      if (!blockEl || blockEl.getAttribute('data-block-id') !== slashState.blockId) {
+        setSlashState(null);
+      }
+    }
+    document.addEventListener('mousedown', onDocMouseDown, true);
+    return () => document.removeEventListener('mousedown', onDocMouseDown, true);
+  }, [slashState]);
+
   // Le slash menu utilise un listener au niveau document en phase capture pour
   // intercepter les touches avant que le contentEditable ne gère ses défauts
   // (sinon ↑/↓ déplacent le caret et Entrée insère une nouvelle ligne).
@@ -804,7 +825,7 @@ export default function BlockEditor({
   }, [slashState, enabledBlocks]);
 
   return (
-    <div className="space-y-2">
+    <div ref={outerRef} className="space-y-2">
       {label && (
         <label className="block text-xs font-medium text-neutral-700 dark:text-neutral-400">
           {label}

src/shared/components/BlockEditor/SlashMenu.client.js

@@ -120,6 +120,7 @@ export default function SlashMenu({
   return (
     <div
       ref={listRef}
+      data-slash-menu
       className="fixed z-50 overflow-y-auto rounded-lg border border-neutral-200 dark:border-neutral-700 bg-white dark:bg-neutral-900 shadow-md py-1"
       style={{ top, left, width: MENU_WIDTH, maxHeight }}
       onMouseDown={(e) => e.preventDefault()} // ne pas voler le focus