fix(ui): improve slash menu keyboard handling and adaptive positioning

- move slash menu keyboard listener to document capture phase to prevent contentEditable default behaviors
- use circular navigation for arrow keys in slash menu
- separate undo/redo shortcuts into dedicated global keydown handler
- add adaptive positioning for slash menu with flip-up, horizontal clamp, and max-height constraints

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

@@ -407,38 +407,8 @@ export default function BlockEditor({
     commitChange(next, { immediate: true });
   }
 
-  // --- Raccourcis globaux ---
+  // --- Raccourcis globaux (Undo/Redo seulement) ---
   function handleGlobalKeyDown(e) {
-    // Slash menu : navigation et sélection
-    if (slashState) {
-      const items = getSlashItems(slashState.query, enabledBlocks);
-      if (e.key === 'ArrowDown') {
-        e.preventDefault();
-        setSlashState(s => ({ ...s, selectedIndex: Math.min((s.selectedIndex ?? 0) + 1, Math.max(items.length - 1, 0)) }));
-        return;
-      }
-      if (e.key === 'ArrowUp') {
-        e.preventDefault();
-        setSlashState(s => ({ ...s, selectedIndex: Math.max((s.selectedIndex ?? 0) - 1, 0) }));
-        return;
-      }
-      if (e.key === 'Enter') {
-        if (items.length > 0) {
-          e.preventDefault();
-          e.stopPropagation();
-          const def = items[slashState.selectedIndex ?? 0];
-          if (def) handleSlashSelect(def.type);
-          return;
-        }
-      }
-      if (e.key === 'Escape') {
-        e.preventDefault();
-        setSlashState(null);
-        return;
-      }
-    }
-
-    // Undo / Redo
     if ((e.ctrlKey || e.metaKey) && e.key === 'z') {
       e.preventDefault();
       if (e.shiftKey) handleRedo();
@@ -452,6 +422,45 @@ export default function BlockEditor({
     }
   }
 
+  // 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).
+  useEffect(() => {
+    if (!slashState) return;
+    function onKey(e) {
+      if (!slashState) return;
+      const items = getSlashItems(slashState.query, enabledBlocks);
+      if (e.key === 'ArrowDown') {
+        e.preventDefault();
+        e.stopPropagation();
+        setSlashState(s => s && ({
+          ...s,
+          selectedIndex: items.length === 0 ? 0 : ((s.selectedIndex ?? 0) + 1) % items.length,
+        }));
+      } else if (e.key === 'ArrowUp') {
+        e.preventDefault();
+        e.stopPropagation();
+        setSlashState(s => s && ({
+          ...s,
+          selectedIndex: items.length === 0 ? 0 : ((s.selectedIndex ?? 0) - 1 + items.length) % items.length,
+        }));
+      } else if (e.key === 'Enter') {
+        if (items.length > 0) {
+          e.preventDefault();
+          e.stopPropagation();
+          const def = items[slashState.selectedIndex ?? 0];
+          if (def) handleSlashSelect(def.type);
+        }
+      } else if (e.key === 'Escape') {
+        e.preventDefault();
+        e.stopPropagation();
+        setSlashState(null);
+      }
+    }
+    document.addEventListener('keydown', onKey, true);
+    return () => document.removeEventListener('keydown', onKey, true);
+  }, [slashState, enabledBlocks]);
+
   return (
     <div className="space-y-2">
       {label && (

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

@@ -1,6 +1,10 @@
 'use client';
 
-import React, { useEffect, useMemo, useRef, useState } from 'react';
+import React, { useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react';
+
+const MENU_WIDTH = 256;       // w-64
+const MENU_MAX_HEIGHT = 288;  // max-h-72
+const VIEWPORT_MARGIN = 8;
 import { listBlocks } from './blockRegistry.js';
 
 // Menu flottant des commandes. Affiché ancré à un élément (anchorRect).
@@ -45,23 +49,51 @@ export default function SlashMenu({
   }, [allowed, query]);
 
   const listRef = useRef(null);
+  const [position, setPosition] = useState({ top: 0, left: 0, maxHeight: MENU_MAX_HEIGHT });
 
-  // Scroll l'élément sélectionné dans la vue
+  // Scroll l'élément sélectionné dans la vue (interne au menu uniquement)
   useEffect(() => {
     const el = listRef.current?.querySelector(`[data-slash-index="${selectedIndex}"]`);
     if (el) el.scrollIntoView({ block: 'nearest' });
   }, [selectedIndex]);
 
+  // Positionnement adaptatif : flip au-dessus si pas assez de place en bas,
+  // clamp horizontalement, et limite la hauteur à l'espace disponible.
+  useLayoutEffect(() => {
+    if (!anchorRect || typeof window === 'undefined') return;
+    const vh = window.innerHeight;
+    const vw = window.innerWidth;
+    const spaceBelow = vh - anchorRect.bottom - VIEWPORT_MARGIN;
+    const spaceAbove = anchorRect.top - VIEWPORT_MARGIN;
+
+    let top;
+    let maxHeight;
+    if (spaceBelow >= Math.min(MENU_MAX_HEIGHT, 200) || spaceBelow >= spaceAbove) {
+      top = anchorRect.bottom + 6;
+      maxHeight = Math.max(120, Math.min(MENU_MAX_HEIGHT, spaceBelow - 6));
+    } else {
+      maxHeight = Math.max(120, Math.min(MENU_MAX_HEIGHT, spaceAbove - 6));
+      top = anchorRect.top - 6 - maxHeight;
+    }
+
+    let left = anchorRect.left;
+    if (left + MENU_WIDTH + VIEWPORT_MARGIN > vw) {
+      left = Math.max(VIEWPORT_MARGIN, vw - MENU_WIDTH - VIEWPORT_MARGIN);
+    }
+    if (left < VIEWPORT_MARGIN) left = VIEWPORT_MARGIN;
+
+    setPosition({ top, left, maxHeight });
+  }, [anchorRect, items.length]);
+
   if (!anchorRect) return null;
 
-  const top = anchorRect.bottom + 6;
-  const left = anchorRect.left;
+  const { top, left, maxHeight } = position;
 
   if (items.length === 0) {
     return (
       <div
         className="fixed z-50 w-64 rounded-xl border border-neutral-200 dark:border-neutral-700 bg-white dark:bg-neutral-900 shadow-lg p-3 text-sm text-neutral-500"
-        style={{ top, left }}
+        style={{ top, left, maxHeight }}
       >
         Aucune commande pour « {query} »
       </div>
@@ -71,8 +103,8 @@ export default function SlashMenu({
   return (
     <div
       ref={listRef}
-      className="fixed z-50 w-64 max-h-72 overflow-y-auto rounded-xl border border-neutral-200 dark:border-neutral-700 bg-white dark:bg-neutral-900 shadow-lg py-1"
-      style={{ top, left }}
+      className="fixed z-50 w-64 overflow-y-auto rounded-xl border border-neutral-200 dark:border-neutral-700 bg-white dark:bg-neutral-900 shadow-lg py-1"
+      style={{ top, left, maxHeight }}
       onMouseDown={(e) => e.preventDefault()} // ne pas voler le focus
     >
       {items.map((def, i) => {