feat: mobile app complet + flashcards fixes + drag handle améliorations

Mobile app:
- Révision flashcards : liste decks, session flip-card SM-2, couleurs harmonisées web
- Génération flashcards depuis note (FlashcardSheet + route /api/mobile/flashcards/generate)
- Audio Whisper : hook useAudioRecorder reécrit, MicButton avec erreurs
- IA : AISheet (améliorer/clarifier/résumer), TitleSheet (titre automatique)
- Suppression note (soft delete + confirmation Alert)
- Note du jour : titre lisible + HTML (plus JSON TipTap brut)
- Parser TipTap→HTML côté mobile (tipTapToHtml)
- Icône 🎓 dans header note → génération flashcards
- Endpoint flashcardGenerate dans config.ts

Web fixes:
- Bug flashcards groupées par carnet → deck par note (migration + schema)
- Bug filtre 'cartes dues' ignoré (suppression fallback buildSessionQueue)
- Suppression UI création deck manuelle (inutile)
- Fix setViewType is not defined dans home-client.tsx

Drag handle menu:
- Fix : clearNodes() avant transformation (heading→liste/code/citation)
- Ajout : option 'Texte' (paragraphe) dans Transformer en
- Ajout : Monter / Descendre le bloc
- Ajout : Copier le contenu du bloc
- Fix : sous-menu hover stable (délai 200ms)
- Fix : Supprimer en rouge via classe --danger (plus :first-child)
- i18n : nouvelles clés dans 15 locales

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

memento-mobile/components/BottomSheet.tsx

@@ -0,0 +1,80 @@
+/**
+ * BottomSheet — modal bas d'écran respectant le design Momento
+ * Usage:
+ *   <BottomSheet visible={v} onClose={() => setV(false)} title="Titre">
+ *     ...children
+ *   </BottomSheet>
+ */
+import { useEffect, useRef } from 'react'
+import {
+  View, Text, Modal, TouchableOpacity, Animated,
+  Pressable, StyleSheet,
+} from 'react-native'
+import { X } from 'lucide-react-native'
+import { C } from '@/lib/theme'
+
+interface Props {
+  visible: boolean
+  onClose: () => void
+  title?: string
+  children: React.ReactNode
+}
+
+export function BottomSheet({ visible, onClose, title, children }: Props) {
+  const translateY = useRef(new Animated.Value(400)).current
+  const opacity = useRef(new Animated.Value(0)).current
+
+  useEffect(() => {
+    if (visible) {
+      Animated.parallel([
+        Animated.spring(translateY, { toValue: 0, useNativeDriver: true, damping: 20, stiffness: 200 }),
+        Animated.timing(opacity, { toValue: 1, duration: 200, useNativeDriver: true }),
+      ]).start()
+    } else {
+      Animated.parallel([
+        Animated.timing(translateY, { toValue: 400, duration: 220, useNativeDriver: true }),
+        Animated.timing(opacity, { toValue: 0, duration: 200, useNativeDriver: true }),
+      ]).start()
+    }
+  }, [visible])
+
+  return (
+    <Modal visible={visible} transparent animationType="none" onRequestClose={onClose}>
+      <Animated.View style={[s.overlay, { opacity }]}>
+        <Pressable style={StyleSheet.absoluteFill} onPress={onClose} />
+        <Animated.View style={[s.sheet, { transform: [{ translateY }] }]}>
+          {/* Handle bar */}
+          <View style={s.handle} />
+          {title && (
+            <View style={s.titleRow}>
+              <Text style={s.title}>{title}</Text>
+              <TouchableOpacity onPress={onClose} style={s.closeBtn} hitSlop={{ top: 8, bottom: 8, left: 8, right: 8 }}>
+                <X size={18} color={C.concrete} />
+              </TouchableOpacity>
+            </View>
+          )}
+          {children}
+        </Animated.View>
+      </Animated.View>
+    </Modal>
+  )
+}
+
+const s = StyleSheet.create({
+  overlay: { flex: 1, backgroundColor: 'rgba(26,26,24,0.5)', justifyContent: 'flex-end' },
+  sheet: {
+    backgroundColor: C.paper,
+    borderTopLeftRadius: 24,
+    borderTopRightRadius: 24,
+    paddingBottom: 32,
+    shadowColor: '#000',
+    shadowOffset: { width: 0, height: -4 },
+    shadowOpacity: 0.12,
+    shadowRadius: 16,
+    elevation: 16,
+  },
+  handle: { width: 36, height: 4, backgroundColor: C.border, borderRadius: 2, alignSelf: 'center', marginTop: 12, marginBottom: 4 },
+  titleRow: { flexDirection: 'row', alignItems: 'center', paddingHorizontal: 20, paddingVertical: 14, borderBottomWidth: 1, borderBottomColor: C.border },
+  title: { flex: 1, fontSize: 15, fontWeight: '700', color: C.ink },
+  closeBtn: { padding: 2 },
+})