feat: AI Overview recherche + AI Writer inline streaming

- AI Overview : synthèse IA en haut des résultats de recherche (Ctrl+K)
  - Service search-overview.service.ts
  - Endpoint /api/ai/search-overview
  - Carte 'Réponse IA' avec Sparkles en haut du panneau gauche
  - Pur additif, ne modifie pas le classement des résultats
- AI Writer inline : slash menu → 'Écrire avec l'IA' → champ inline
  - Mode 'write' dans paragraph-refactor.service.ts
  - Streaming paragraphe par paragraphe (120ms delay)
  - Nettoyage HTML (espaces vides supprimés)
  - Ref synchrone pour éviter fermeture du menu pendant la frappe
- Fix: index slashCommands AI Writer corrigé
- Fix: Loader2 import manquant
- i18n FR/EN

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

@@ -69,7 +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, Columns3
+  ChevronsRightLeft, MessageSquareWarning, ListTree, FunctionSquare, Columns3, Loader2
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { toast } from 'sonner'
@@ -1677,7 +1677,8 @@ 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 [aiWriterMode, setAiWriterMode] = useState(false)
+  const aiWriterModeRef = useRef(false)
   const [aiWriterPrompt, setAiWriterPrompt] = useState('')
   const [aiWriterLoading, setAiWriterLoading] = useState(false)
   const menuRef = useRef<HTMLDivElement>(null)
@@ -1736,9 +1737,48 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
   ]
 
   const closeMenu = useCallback(() => {
-    setIsOpen(false); setQuery(''); setSelectedIndex(0); setActiveCategory(null)
+    setIsOpen(false); setQuery(''); setSelectedIndex(0); setActiveCategory(null); setAiWriterMode(false); aiWriterModeRef.current = false
   }, [])
 
+  const handleAiWriterSubmit = useCallback(async () => {
+    if (!aiWriterPrompt.trim()) return
+    setAiWriterLoading(true)
+    try {
+      const res = await fetch('/api/ai/reformulate', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          text: '',
+          option: 'write',
+          format: 'html',
+          writePrompt: aiWriterPrompt.trim(),
+        }),
+      })
+      const data = await res.json()
+      if (!res.ok) { toast.error(data.error || 'Erreur'); return }
+      let html = data.reformulatedText || data.text || ''
+      // Clean up excessive whitespace
+      html = html
+        .replace(/<p>\s*<\/p>/g, '')
+        .replace(/(<p[^>]*>)\s+/g, '$1')
+        .replace(/\s+(<\/p>)/g, '$1')
+        .replace(/\n{3,}/g, '\n\n')
+        .trim()
+
+      closeMenu()
+
+      // Stream the content paragraph by paragraph
+      const paragraphs = html.match(/<(?:p|h[1-3]|ul|ol|div|blockquote|pre)[^>]*>[\s\S]*?<\/(?:p|h[1-3]|ul|ol|div|blockquote|pre)>/gi) || [html]
+      for (let i = 0; i < paragraphs.length; i++) {
+        editor.chain().focus().insertContent(paragraphs[i]).run()
+        if (i < paragraphs.length - 1) {
+          await new Promise(r => setTimeout(r, 120))
+        }
+      }
+    } catch (e: any) { toast.error(e.message || 'Erreur') }
+    finally { setAiWriterLoading(false) }
+  }, [aiWriterPrompt, editor, closeMenu])
+
   const deleteSlashText = useCallback(() => {
     const { from, to } = editor.state.selection
     const textBefore = editor.state.doc.textBetween(Math.max(0, from - 50), from, '\n')
@@ -1767,9 +1807,13 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     if (item.isImage) {
       deleteSlashText(); closeMenu(); onInsertImage(editor)
     } else if (item.isAi && item.aiOption === 'write') {
-      deleteSlashText(); closeMenu()
-      setAiWriterOpen(true)
+      aiWriterModeRef.current = true
+      setAiWriterMode(true)
       setAiWriterPrompt('')
+      deleteSlashText()
+      const { from } = editor.state.selection
+      const c = editor.view.coordsAtPos(from)
+      setCoords({ top: c.bottom + 8, left: c.left })
     } else if (item.isAi && item.aiOption) {
       deleteSlashText(); closeMenu(); setAiLoading(true)
       try {
@@ -1797,43 +1841,6 @@ 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
@@ -1913,6 +1920,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
   useEffect(() => {
     const handleKeyDown = (e: KeyboardEvent) => {
       if (!isOpen) return
+      if (aiWriterModeRef.current) return  // Let the AI writer input handle keystrokes
       if (e.key === 'ArrowDown') { e.preventDefault(); setSelectedIndex(i => (i + 1) % filtered.length); return }
       if (e.key === 'ArrowUp') { e.preventDefault(); setSelectedIndex(i => (i - 1 + filtered.length) % filtered.length); return }
       if (e.key === 'ArrowRight' || e.key === 'ArrowLeft') {
@@ -1973,7 +1981,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
 
   useEffect(() => {
     const handleClick = (e: MouseEvent) => {
-      if (isOpen && menuRef.current && !menuRef.current.contains(e.target as Node)) {
+      if (isOpen && !aiWriterModeRef.current && menuRef.current && !menuRef.current.contains(e.target as Node)) {
         closeMenu()
       }
     }
@@ -1985,6 +1993,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
     const handler = () => {
       // Ignore events fired while user clicks inside the menu
       if (menuInteracting.current) return
+      if (aiWriterModeRef.current) return  // Synchronous check via ref
       const { from, empty } = editor.state.selection
       if (!empty) { if (isOpen) closeMenu(); return }
       const text = editor.state.doc.textBetween(Math.max(0, from - 50), from, '\n')
@@ -1992,16 +2001,16 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
       if (m) {
         setQuery(m[1])
         setSelectedIndex(0)
-        if (!isOpen) { setIsOpen(true); setActiveCategory(null) } // reset category filter on fresh open
+        if (!isOpen) { setIsOpen(true); setActiveCategory(null) }
       }
       else if (isOpen) closeMenu()
     }
     editor.on('update', handler)
     editor.on('selectionUpdate', handler)
     return () => { editor.off('update', handler); editor.off('selectionUpdate', handler) }
-  }, [editor, isOpen, closeMenu])
+  }, [editor, isOpen, closeMenu, aiWriterMode])
 
-  if (!isOpen || filtered.length === 0) return null
+  if (!aiWriterMode && (!isOpen || filtered.length === 0)) return null
 
   let flatIndex = -1
   const sectionIds = ORDERED_SLASH_CATEGORIES.filter(id => (categories[id]?.length ?? 0) > 0)
@@ -2021,6 +2030,42 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
 
   return createPortal(
     <>
+      {aiWriterMode ? (
+        <div
+          ref={menuRef}
+          className="notion-slash-menu"
+          style={{ top: coords.top, left: coords.left, minWidth: '360px' }}
+          onClick={(e) => e.stopPropagation()}
+          dir="auto"
+        >
+          <div className="flex items-center gap-2 px-3 py-2.5 border-b border-border/30">
+            <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.shiftKey) { e.preventDefault(); void handleAiWriterSubmit() }
+                if (e.key === 'Escape') closeMenu()
+              }}
+              autoFocus
+              disabled={aiWriterLoading}
+              placeholder={t('richTextEditor.aiWriterPlaceholder') || 'Décris ce que tu veux écrire...'}
+              className="flex-1 bg-transparent text-sm outline-none placeholder:text-muted-foreground"
+            />
+            {aiWriterLoading && <Loader2 size={14} className="animate-spin text-brand-accent flex-shrink-0" />}
+          </div>
+          {!aiWriterLoading && aiWriterPrompt.trim() && (
+            <button
+              onClick={() => void handleAiWriterSubmit()}
+              className="w-full px-3 py-2 text-xs font-medium text-brand-accent hover:bg-brand-accent/10 transition-colors text-left"
+            >
+              {t('general.send') || 'Générer'} ↵
+            </button>
+          )}
+        </div>
+      ) : (
       <div
         ref={menuRef}
         className="notion-slash-menu"
@@ -2112,6 +2157,7 @@ function SlashCommandMenu({ editor, onInsertImage, onSuggestCharts }: { editor:
           )
         })}
       </div>
+      )}
 
       {showPreview && (
         <div
@@ -2121,51 +2167,6 @@ 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
   )