feat: AI Writer inline — génère du contenu au curseur

- Mode 'write' ajouté à paragraph-refactor.service.ts
- Endpoint /api/ai/reformulate étendu (option 'write' + writePrompt)
- UI : champ de prompt inline apparaît au curseur après slash menu
  - Tape / → 'Écrire avec l'IA' → décrit ce que tu veux → Entrée
  - L'IA génère et insère le contenu à la position du curseur
- Pas de migration DB, réutilise l'infra existante
- i18n FR/EN

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

@@ -109,7 +109,7 @@ type SlashItem = {
   shortcut?: string
   isImage?: boolean
   isAi?: boolean
-  aiOption?: 'clarify' | 'shorten' | 'improve'
+  aiOption?: 'clarify' | 'shorten' | 'improve' | 'write'
   command: (editor: Editor, range?: any) => void
 }
 
@@ -173,7 +173,12 @@ const slashCommands: SlashItem[] = [
   { title: 'Clarifier', description: 'Rendre le texte plus clair', icon: Lightbulb, category: 'IA Note', isAi: true, aiOption: 'clarify', command: () => { } },
   { title: 'Raccourcir', description: 'Condenser le texte', icon: Scissors, category: 'IA Note', isAi: true, aiOption: 'shorten', command: () => { } },
   { title: 'Améliorer', description: 'Améliorer le style', icon: Wand2, category: 'IA Note', isAi: true, aiOption: 'improve', command: () => { } },
-  { title: 'Développer', description: 'Élaborer et enrichir le texte', icon: Expand, category: 'IA Note', isAi: true, aiOption: 'clarify', command: () => { } },
+  {
+    title: 'Développer', description: 'Élaborer et enrichir le texte', icon: Expand, category: 'IA Note', isAi: true, aiOption: 'clarify', command: () => { }
+  },
+  {
+    title: 'Écrire avec l\'IA', description: 'Générer du contenu au curseur', icon: Sparkles, category: 'IA Note', isAi: true, aiOption: 'write', command: () => { }
+  },
   // Formatting extensions
   { title: 'Bold', description: 'Make text bold', icon: Bold, category: 'Formatting', command: (e) => e.chain().focus().toggleBold().run() },
   { title: 'Italic', description: 'Make text italic', icon: Italic, category: 'Formatting', command: (e) => e.chain().focus().toggleItalic().run() },
@@ -1672,6 +1677,9 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
   const [coords, setCoords] = useState({ top: 0, left: 0 })
   const [previewCoords, setPreviewCoords] = useState({ top: 0, left: 0, side: 'right' as 'right' | 'left' })
   const [aiLoading, setAiLoading] = useState(false)
+  const [aiWriterOpen, setAiWriterOpen] = useState(false)
+  const [aiWriterPrompt, setAiWriterPrompt] = useState('')
+  const [aiWriterLoading, setAiWriterLoading] = useState(false)
   const menuRef = useRef<HTMLDivElement>(null)
   const selectedItemRef = useRef<HTMLButtonElement>(null)
   const menuInteracting = useRef(false)
@@ -1715,6 +1723,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     { ...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'] },
+    { ...slashCommands[37], title: t('richTextEditor.slashAiWriter') || 'Écrire avec l\'IA', description: t('richTextEditor.slashAiWriterDesc') || 'Générer du contenu au curseur', categoryId: 'ai', slashKeywords: ['ecrire', 'écrire', 'write', 'ia', 'ai', 'generer', 'générer', 'rediger', 'rédiger'] },
     {
       title: t('richTextEditor.slashNoteLink'),
       description: t('richTextEditor.slashNoteLinkDesc'),
@@ -1757,6 +1766,10 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     }
     if (item.isImage) {
       deleteSlashText(); closeMenu(); onInsertImage(editor)
+    } else if (item.isAi && item.aiOption === 'write') {
+      deleteSlashText(); closeMenu()
+      setAiWriterOpen(true)
+      setAiWriterPrompt('')
     } else if (item.isAi && item.aiOption) {
       deleteSlashText(); closeMenu(); setAiLoading(true)
       try {
@@ -1784,6 +1797,43 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     }
   }, [editor, closeMenu, deleteSlashText, onInsertImage, onSuggestCharts, t, requestAiConsent])
 
+  const handleAiWriterSubmit = useCallback(async () => {
+    if (!aiWriterPrompt.trim() || !editor) return
+    setAiWriterLoading(true)
+    try {
+      const consented = await requestAiConsent()
+      if (!consented) return
+
+      const noteTitle = (editor.storage as any).structuredViewBlock?.noteTitle || ''
+      const res = await fetch('/api/ai/reformulate', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          text: noteTitle,
+          option: 'write',
+          format: 'html',
+          language: 'Francais',
+          writePrompt: aiWriterPrompt.trim(),
+        }),
+      })
+      const data = await res.json()
+      if (!res.ok) {
+        toast.error(data.error || 'Erreur')
+        return
+      }
+      const html = data.reformulatedText || data.text || ''
+      if (html) {
+        editor.chain().focus().insertContent(html).run()
+      }
+      setAiWriterOpen(false)
+      setAiWriterPrompt('')
+    } catch (err: any) {
+      toast.error(err.message || 'Erreur')
+    } finally {
+      setAiWriterLoading(false)
+    }
+  }, [aiWriterPrompt, editor, requestAiConsent])
+
   // Charger les favoris fréquents lors de l'ouverture
   useEffect(() => {
     if (!isOpen) return
@@ -2071,6 +2121,51 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
           <SlashPreview itemTitle={selectedItem.title} />
         </div>
       )}
+
+      {aiWriterOpen && createPortal(
+        <div
+          className="fixed z-[9999] flex items-center gap-2 rounded-xl border border-brand-accent/30 bg-card shadow-xl px-3 py-2"
+          style={{
+            top: (() => {
+              const { from } = editor.state.selection
+              const c = editor.view.coordsAtPos(from)
+              return c.bottom + 4
+            })(),
+            left: (() => {
+              const { from } = editor.state.selection
+              const c = editor.view.coordsAtPos(from)
+              return Math.min(c.left, window.innerWidth - 420)
+            })(),
+          }}
+          dir="auto"
+        >
+          <Sparkles size={16} className="text-brand-accent flex-shrink-0" />
+          <input
+            type="text"
+            value={aiWriterPrompt}
+            onChange={(e) => setAiWriterPrompt(e.target.value)}
+            onKeyDown={(e) => {
+              e.stopPropagation()
+              if (e.key === 'Enter') { e.preventDefault(); handleAiWriterSubmit() }
+              if (e.key === 'Escape') { setAiWriterOpen(false); setAiWriterPrompt('') }
+            }}
+            autoFocus
+            disabled={aiWriterLoading}
+            placeholder={t('richTextEditor.aiWriterPlaceholder') || 'Décris ce que tu veux écrire...'}
+            className="flex-1 min-w-[300px] bg-transparent text-sm outline-none placeholder:text-muted-foreground"
+          />
+          {aiWriterLoading && <Loader2 size={14} className="animate-spin text-brand-accent flex-shrink-0" />}
+          {!aiWriterLoading && aiWriterPrompt.trim() && (
+            <button
+              onClick={handleAiWriterSubmit}
+              className="text-xs font-medium text-brand-accent hover:underline flex-shrink-0"
+            >
+              {t('general.send') || '→'}
+            </button>
+          )}
+        </div>,
+        document.body
+      )}
     </>,
     document.body
   )