feat: Link Preview block (carte aperçu URL) + proxy images

- Bloc Link Preview : colle une URL → carte avec titre, description, image, favicon
- API /api/link-preview : extraction OpenGraph + meta tags
- API /api/image-proxy : contourne le hotlinking (Referer spoofing)
- Métadonnées persistées en HTML (data-preview JSON) — pas de refetch au reload
- Texte indexable : titre + description + URL inclus pour recherche/embeddings
- Modal propre pour saisir l'URL (plus de prompt())
- Slash menu + smart paste 'Coller comme carte aperçu'
- i18n FR/EN complet
- Fix: bouton calendrier retiré du sélecteur de vue

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

@@ -30,6 +30,7 @@ import { ToggleExtension, insertToggleBlock } from './tiptap-toggle-extension'
 import { CalloutExtension, insertCalloutBlock } from './tiptap-callout-extension'
 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 { RtlPreserveExtension } from './tiptap-rtl-preserve-extension'
 import { ClipArticleExtension } from './tiptap-clip-article-extension'
 import { BlockPicker, type BlockSuggestion } from './block-picker'
@@ -219,6 +220,12 @@ const slashCommands: SlashItem[] = [
     title: 'Outline', description: 'Table of contents from headings', icon: ListTree, category: 'Basic blocks', shortcut: '/toc',
     command: (e) => { insertOutlineBlock(e) },
   },
+  {
+    title: 'Link Preview', description: 'Embed a URL as a rich card', icon: Link2, category: 'Basic blocks', shortcut: '/link',
+    command: (e) => {
+      window.dispatchEvent(new CustomEvent('memento-open-link-preview'))
+    },
+  },
 ]
 
 async function aiReformulate(text: string, option: string, t: any, language?: string): Promise<string> {
@@ -308,6 +315,13 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
     const [isMobile, setIsMobile] = useState(false)
     const [actionSheetOpen, setActionSheetOpen] = useState(false)
     const [showFindReplace, setShowFindReplace] = useState(false)
+    const [linkPreviewUrl, setLinkPreviewUrl] = useState<string | null>(null)
+
+    useEffect(() => {
+      const handler = () => setLinkPreviewUrl('')
+      window.addEventListener('memento-open-link-preview', handler)
+      return () => window.removeEventListener('memento-open-link-preview', handler)
+    }, [])
 
     useEffect(() => {
       const handleFindShortcut = (e: KeyboardEvent) => {
@@ -458,6 +472,7 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
         CalloutExtension,
         OutlineExtension,
         FindReplaceExtension,
+        LinkPreviewExtension,
         ClipArticleExtension,
         RtlPreserveExtension,
         Placeholder.configure({
@@ -1118,6 +1133,50 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
           <FindReplaceBar editor={editor} onClose={() => setShowFindReplace(false)} />
         )}
 
+        {editor && linkPreviewUrl !== null && (
+          <div className="fixed inset-0 z-[9998] flex items-center justify-center bg-black/30" onClick={() => setLinkPreviewUrl(null)}>
+            <div className="bg-popover rounded-xl border border-border shadow-lg w-96 max-w-[90vw] p-4" onClick={(e) => e.stopPropagation()} dir="auto">
+              <div className="text-sm font-medium mb-3">{t('richTextEditor.linkPreviewModalTitle')}</div>
+              <input
+                type="url"
+                autoFocus
+                value={linkPreviewUrl}
+                onChange={(e) => setLinkPreviewUrl(e.target.value)}
+                onKeyDown={(e) => {
+                  e.stopPropagation()
+                  if (e.key === 'Enter') {
+                    e.preventDefault()
+                    if (linkPreviewUrl.trim()) {
+                      insertLinkPreview(editor, linkPreviewUrl.trim())
+                      setLinkPreviewUrl(null)
+                    }
+                  }
+                  if (e.key === 'Escape') setLinkPreviewUrl(null)
+                }}
+                placeholder="https://..."
+                className="w-full rounded-md border border-border bg-background px-3 py-2 text-sm outline-none focus:ring-2 focus:ring-primary/30"
+              />
+              <div className="flex justify-end gap-2 mt-3">
+                <button onClick={() => setLinkPreviewUrl(null)} className="px-3 py-1.5 text-sm rounded-md hover:bg-muted transition-colors">
+                  {t('richTextEditor.imageModalCancel')}
+                </button>
+                <button
+                  onClick={() => {
+                    if (linkPreviewUrl.trim()) {
+                      insertLinkPreview(editor, linkPreviewUrl.trim())
+                      setLinkPreviewUrl(null)
+                    }
+                  }}
+                  disabled={!linkPreviewUrl.trim()}
+                  className="px-3 py-1.5 text-sm rounded-md bg-primary text-primary-foreground hover:bg-primary/90 disabled:opacity-40 transition-colors"
+                >
+                  {t('richTextEditor.linkPreviewModalInsert')}
+                </button>
+              </div>
+            </div>
+          </div>
+        )}
+
         {editor && blockMenuState && (
           <BlockActionMenu
             editor={editor}
@@ -1150,6 +1209,7 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
             isImage={smartPasteExtended.isImage}
             isVideo={smartPasteExtended.isVideo}
             onLink={() => handlePasteUrlLink(smartPasteExtended.text)}
+            onLinkPreview={() => { insertLinkPreview(editor, smartPasteExtended.text); setSmartPasteExtended(null) }}
             onImage={() => handlePasteUrlImage(smartPasteExtended.text)}
             onVideo={() => handlePasteUrlVideo(smartPasteExtended.text)}
             onCodeBlock={() => handlePasteCodeBlock(smartPasteExtended.text)}
@@ -1634,6 +1694,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     { ...slashCommands[31], title: t('richTextEditor.slashToggle'), description: t('richTextEditor.slashToggleDesc'), categoryId: 'text', slashKeywords: ['toggle', 'accordion', 'replier', 'deroulant', 'déroulant', 'section'] },
     { ...slashCommands[32], title: t('richTextEditor.slashCallout'), description: t('richTextEditor.slashCalloutDesc'), categoryId: 'text', slashKeywords: ['callout', 'encadre', 'encadré', 'info', 'alerte', 'astuce', 'tip', 'warning'] },
     { ...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'] },
     {
       title: t('richTextEditor.slashNoteLink'),
       description: t('richTextEditor.slashNoteLinkDesc'),