feat: colonnes multi-colonnes (layout côte à côte style Notion)

- Architecture nested nodes: columns container → column children
- CSS seamless (pas de bordures, fin séparateur vertical entre colonnes)
- isolating: true sur les deux nœuds (curseur reste dans sa colonne)
- Commands addColumnBefore/addColumnAfter/deleteColumn
- Slash menu + drag handle + raccourci Mod+Shift+L
- i18n FR/EN complet

memento-note/app/globals.css

@@ -3000,4 +3000,37 @@ html.font-system * {
   border-radius: 2px;
   box-shadow: 0 0 0 2px rgba(249, 115, 22, 0.3);
   color: inherit;
-}
+}
+
+/* Multi-column layout — seamless like Notion, no boxes */
+.tiptap-columns {
+  display: flex !important;
+  gap: 24px !important;
+  margin: 8px 0 !important;
+  padding: 0 !important;
+  border: none !important;
+  background: none !important;
+  border-radius: 0 !important;
+}
+
+.tiptap-column {
+  flex: 1 1 0% !important;
+  min-width: 0 !important;
+  padding: 0 !important;
+  border: none !important;
+  border-radius: 0 !important;
+  background: none !important;
+  border-left: 1px solid color-mix(in oklab, var(--foreground) 8%, transparent) !important;
+  padding-left: 24px !important;
+  overflow-wrap: break-word !important;
+  word-break: break-word !important;
+}
+
+.tiptap-column:first-child {
+  border-left: none !important;
+  padding-left: 0 !important;
+}
+
+.tiptap-column > *:first-child { margin-top: 0; }
+.tiptap-column > *:last-child { margin-bottom: 0; }
+.tiptap-column p { margin: 4px 0; }

memento-note/components/block-action-menu.tsx

@@ -14,12 +14,14 @@ import {
   Heading1, Heading2, Heading3, List, ListOrdered,
   CheckSquare, Quote, CodeXml, Database,
   ArrowUp, ArrowDown, AlignLeft, ClipboardCopy, Sparkles,
-  ChevronsRightLeft, MessageSquareWarning, ListTree,
+  ChevronsRightLeft, MessageSquareWarning, ListTree, Columns3,
+  Plus, Minus,
 } from 'lucide-react'
 import { replaceBlockWithStructuredView } from '@/components/tiptap-structured-view-block-extension'
 import { insertToggleBlock, turnIntoToggleBlock } from '@/components/tiptap-toggle-extension'
 import { turnIntoCalloutBlock } from '@/components/tiptap-callout-extension'
 import { insertOutlineBlock } from '@/components/tiptap-outline-extension'
+import { insertColumnsBlock } from '@/components/tiptap-columns-extension'
 
 interface BlockActionMenuProps {
   editor: Editor
@@ -391,6 +393,12 @@ export function BlockActionMenu({
         <span>{t('richTextEditor.slashOutline')}</span>
       </button>
 
+      {/* Colonnes */}
+      <button type="button" className="block-action-item" onClick={() => { insertColumnsBlock(editor, 2); onClose() }}>
+        <Columns3 size={16} />
+        <span>{t('richTextEditor.slashColumns')}</span>
+      </button>
+
       <div className="block-action-separator" />
 
       {/* Création de diagramme */}

memento-note/components/rich-text-editor.tsx

@@ -32,6 +32,7 @@ import { OutlineExtension, insertOutlineBlock } from './tiptap-outline-extension
 import { FindReplaceBar, FindReplaceExtension } from './editor-find-replace-bar'
 import { LinkPreviewExtension, insertLinkPreview, isUrl } from './tiptap-link-preview-extension'
 import { MathEquationExtension, InlineMathExtension, insertMathEquation } from './tiptap-math-extension'
+import { ColumnsExtension, ColumnNode, insertColumnsBlock } from './tiptap-columns-extension'
 import { RtlPreserveExtension } from './tiptap-rtl-preserve-extension'
 import { ClipArticleExtension } from './tiptap-clip-article-extension'
 import { BlockPicker, type BlockSuggestion } from './block-picker'
@@ -68,7 +69,7 @@ import {
   FileText, Pilcrow, MessageSquare, AlignLeft, AlignCenter, AlignRight,
   Superscript as SuperscriptIcon, Subscript as SubscriptIcon, Expand, Plus,
   SpellCheck, Languages, BookOpen, Presentation, BarChart3, Database,
-  ChevronsRightLeft, MessageSquareWarning, ListTree, FunctionSquare
+  ChevronsRightLeft, MessageSquareWarning, ListTree, FunctionSquare, Columns3
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { toast } from 'sonner'
@@ -231,6 +232,10 @@ const slashCommands: SlashItem[] = [
     title: 'Math', description: 'LaTeX equation block', icon: FunctionSquare, category: 'Basic blocks', shortcut: '$$',
     command: (e) => { insertMathEquation(e) },
   },
+  {
+    title: 'Columns', description: 'Side-by-side layout', icon: Columns3, category: 'Basic blocks', shortcut: '/cols',
+    command: (e) => { insertColumnsBlock(e, 2) },
+  },
 ]
 
 async function aiReformulate(text: string, option: string, t: any, language?: string): Promise<string> {
@@ -480,6 +485,8 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
         LinkPreviewExtension,
         MathEquationExtension,
         InlineMathExtension,
+        ColumnsExtension,
+        ColumnNode,
         ClipArticleExtension,
         RtlPreserveExtension,
         Placeholder.configure({
@@ -1703,6 +1710,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     { ...slashCommands[33], title: t('richTextEditor.slashOutline'), description: t('richTextEditor.slashOutlineDesc'), categoryId: 'text', slashKeywords: ['outline', 'sommaire', 'toc', 'table', 'matieres', 'matières', 'plan'] },
     { ...slashCommands[34], title: t('richTextEditor.slashLinkPreview'), description: t('richTextEditor.slashLinkPreviewDesc'), categoryId: 'embed', slashKeywords: ['link', 'lien', 'url', 'preview', 'apercu', 'aperçu', 'embed', 'card', 'carte'] },
     { ...slashCommands[35], title: t('richTextEditor.slashMath'), description: t('richTextEditor.slashMathDesc'), categoryId: 'text', slashKeywords: ['math', 'maths', 'equation', 'équation', 'formula', 'formule', 'latex', 'katex'] },
+    { ...slashCommands[36], title: t('richTextEditor.slashColumns'), description: t('richTextEditor.slashColumnsDesc'), categoryId: 'text', slashKeywords: ['columns', 'colonnes', 'cols', 'layout', 'mise', 'page', 'cote', 'côte'] },
     {
       title: t('richTextEditor.slashNoteLink'),
       description: t('richTextEditor.slashNoteLinkDesc'),

memento-note/components/tiptap-columns-extension.tsx

@@ -0,0 +1,159 @@
+'use client'
+
+import { Node, mergeAttributes, findParentNode } from '@tiptap/core'
+import { TextSelection } from '@tiptap/pm/state'
+import type { EditorState, Transaction } from '@tiptap/pm/state'
+import type { Node as PMNode } from '@tiptap/pm/model'
+
+export const ColumnNode = Node.create({
+  name: 'column',
+  content: 'block+',
+  isolating: true,
+  defining: true,
+
+  addAttributes() {
+    return {
+      index: {
+        default: 0,
+        parseHTML: (el) => Number(el.getAttribute('index')) || 0,
+        renderHTML: (attrs) => ({ index: attrs.index }),
+      },
+    }
+  },
+
+  parseHTML() {
+    return [{ tag: 'div[data-type="column"]' }]
+  },
+
+  renderHTML({ HTMLAttributes }) {
+    return [
+      'div',
+      mergeAttributes(HTMLAttributes, {
+        'data-type': 'column',
+        class: 'tiptap-column',
+      }),
+      0,
+    ]
+  },
+})
+
+export const ColumnsExtension = Node.create({
+  name: 'columns',
+  group: 'block',
+  content: 'column{1,}',
+  isolating: true,
+  defining: true,
+  allowGapCursor: false,
+
+  addAttributes() {
+    return {
+      cols: {
+        default: 2,
+        parseHTML: (el) => Number(el.getAttribute('cols')) || 2,
+        renderHTML: (attrs) => ({ cols: attrs.cols }),
+      },
+    }
+  },
+
+  parseHTML() {
+    return [{ tag: 'div[data-type="columns"]' }]
+  },
+
+  renderHTML({ HTMLAttributes }) {
+    return [
+      'div',
+      mergeAttributes(HTMLAttributes, {
+        'data-type': 'columns',
+        class: 'tiptap-columns',
+      }),
+      0,
+    ]
+  },
+
+  addCommands() {
+    return {
+      addColumnAfter: () => ({ state, dispatch }: { state: EditorState; dispatch?: (tr: Transaction) => void }) => {
+        return addOrDeleteCol(state, dispatch, 'addAfter')
+      },
+      addColumnBefore: () => ({ state, dispatch }: { state: EditorState; dispatch?: (tr: Transaction) => void }) => {
+        return addOrDeleteCol(state, dispatch, 'addBefore')
+      },
+      deleteColumn: () => ({ state, dispatch }: { state: EditorState; dispatch?: (tr: Transaction) => void }) => {
+        return addOrDeleteCol(state, dispatch, 'delete')
+      },
+    }
+  },
+
+  addKeyboardShortcuts() {
+    return {
+      'Mod-Shift-L': () => this.editor.commands.insertContent({
+        type: this.name,
+        attrs: { cols: 2 },
+        content: [
+          { type: 'column', attrs: { index: 0 }, content: [{ type: 'paragraph' }] },
+          { type: 'column', attrs: { index: 1 }, content: [{ type: 'paragraph' }] },
+        ],
+      }),
+    }
+  },
+})
+
+function addOrDeleteCol(state: EditorState, dispatch?: (tr: Transaction) => void, type?: 'addBefore' | 'addAfter' | 'delete'): boolean {
+  const maybeColumns = findParentNode((node: PMNode) => node.type.name === 'columns')(state.selection)
+  const maybeColumn = findParentNode((node: PMNode) => node.type.name === 'column')(state.selection)
+
+  if (!maybeColumns || !maybeColumn) return false
+
+  const cols = maybeColumns.node
+  const colIndex = maybeColumn.node.attrs.index
+  const colsJSON = cols.toJSON()
+
+  let nextIndex = colIndex
+
+  if (type === 'delete') {
+    if (colsJSON.content.length <= 1) return false
+    nextIndex = Math.max(0, colIndex - 1)
+    colsJSON.content.splice(colIndex, 1)
+  } else {
+    nextIndex = type === 'addBefore' ? colIndex : colIndex + 1
+    colsJSON.content.splice(nextIndex, 0, {
+      type: 'column',
+      attrs: { index: colIndex },
+      content: [{ type: 'paragraph' }],
+    })
+  }
+
+  colsJSON.attrs.cols = colsJSON.content.length
+  colsJSON.content.forEach((colJSON: any, index: number) => {
+    colJSON.attrs.index = index
+  })
+
+  const nextCols = PMNode.fromJSON(state.schema, colsJSON)
+
+  let nextSelectPos = maybeColumns.pos + 1
+  nextCols.content.forEach((col: PMNode, _pos: number, index: number) => {
+    if (index < nextIndex) nextSelectPos += col.nodeSize
+  })
+
+  if (dispatch) {
+    const tr = state.tr
+    tr.replaceWith(maybeColumns.pos, maybeColumns.pos + maybeColumns.node.nodeSize, nextCols)
+    tr.setSelection(TextSelection.near(tr.doc.resolve(nextSelectPos + 1)))
+    dispatch(tr)
+  }
+
+  return true
+}
+
+export function insertColumnsBlock(editor: any, columns: number = 2) {
+  const content = Array.from({ length: columns }, (_, i) => ({
+    type: 'column',
+    attrs: { index: i },
+    content: [{ type: 'paragraph' }],
+  }))
+  editor.chain().focus().insertContent({
+    type: 'columns',
+    attrs: { cols: columns },
+    content,
+  }).run()
+}

memento-note/locales/en.json

@@ -2445,6 +2445,12 @@
     "mathCancel": "Cancel",
     "mathAi": "Write with AI",
     "mathAiPlaceholder": "Describe the equation in words... (e.g: quadratic formula)",
+    "slashColumns": "Columns",
+    "slashColumnsDesc": "Put content side by side",
+    "columnsRemove": "Remove a column",
+    "columnsAdd": "Add a column",
+    "columnsDelete": "Delete columns",
+    "columnsLabel": "columns",
     "calloutDelete": "Delete callout",
     "calloutUnwrap": "Disable callout",
     "calloutInfo": "Information",

memento-note/locales/fr.json

@@ -2449,6 +2449,12 @@
     "mathCancel": "Annuler",
     "mathAi": "Écrire avec l'IA",
     "mathAiPlaceholder": "Décris l'équation en mots... (ex: formule quadratique)",
+    "slashColumns": "Colonnes",
+    "slashColumnsDesc": "Mettre du contenu côte à côte",
+    "columnsRemove": "Retirer une colonne",
+    "columnsAdd": "Ajouter une colonne",
+    "columnsDelete": "Supprimer les colonnes",
+    "columnsLabel": "colonnes",
     "calloutDelete": "Supprimer l'encadré",
     "calloutUnwrap": "Désactiver l'encadré",
     "calloutInfo": "Information",