feat: smart note history with manual/auto modes, delete entries, i18n fixes

- Add noteHistoryMode setting (manual default / auto) with DB migration
- Manual mode: commit button in editor toolbar creates snapshots on demand
- Auto mode: smart snapshots with 20-char diff threshold + 5min cooldown,
  structural changes (color, pin, archive, labels) bypass cooldown
- Add delete individual history entries from history modal
- Fix sidebar: Notes nav no longer active on notebook pages
- Fix sidebar icon: replace filled Lightbulb with outlined FileText
- Fix title suggestions: change from amber to sky blue color scheme
- Fix hydration mismatch: add suppressHydrationWarning on locale dates
- Complete i18n: add history, sort, and AI chat translations for all 16 languages
- Translate French AI assistant section (40+ keys) from English to French
- Update README with new features and stack info

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/components/ai/ai-settings-panel.tsx

@@ -24,6 +24,8 @@ interface AISettingsPanelProps {
     demoMode: boolean
     languageDetection: boolean
     autoLabeling: boolean
+    noteHistory: boolean
+    noteHistoryMode: 'manual' | 'auto'
   }
 }
 
@@ -179,6 +181,53 @@ export function AISettingsPanel({ initialSettings }: AISettingsPanelProps) {
           onChange={(checked) => handleToggle('autoLabeling', checked)}
         />
 
+        <FeatureToggle
+          name="Historique des notes"
+          description="Active les snapshots de versions et la restauration depuis History"
+          checked={settings.noteHistory ?? false}
+          onChange={(checked) => handleToggle('noteHistory', checked)}
+        />
+
+        {settings.noteHistory && (
+          <div className="space-y-2 rounded-lg border border-border/50 bg-muted/30 p-3">
+            <p className="text-sm font-medium">{t('notes.historyMode') || 'Mode d\'historique'}</p>
+            <RadioGroup
+              value={settings.noteHistoryMode ?? 'manual'}
+              onValueChange={(value) => {
+                const mode = value as 'manual' | 'auto'
+                setSettings((s) => ({ ...s, noteHistoryMode: mode }))
+                updateAISettings({ noteHistoryMode: mode }).then(() => {
+                  toast.success(t('settings.settingsSaved') || 'Saved')
+                })
+              }}
+              className="space-y-2"
+            >
+              <div className="flex items-start gap-2">
+                <RadioGroupItem value="manual" id="history-manual" />
+                <div className="grid gap-0.5 leading-none">
+                  <Label htmlFor="history-manual" className="text-sm font-medium">
+                    {t('notes.historyModeManual') || 'Manuel'}
+                  </Label>
+                  <p className="text-xs text-muted-foreground">
+                    {t('notes.historyModeManualDesc') || 'Créer des snapshots avec le bouton commit'}
+                  </p>
+                </div>
+              </div>
+              <div className="flex items-start gap-2">
+                <RadioGroupItem value="auto" id="history-auto" />
+                <div className="grid gap-0.5 leading-none">
+                  <Label htmlFor="history-auto" className="text-sm font-medium">
+                    {t('notes.historyModeAuto') || 'Automatique'}
+                  </Label>
+                  <p className="text-xs text-muted-foreground">
+                    {t('notes.historyModeAutoDesc') || 'Snapshots automatiques avec détection intelligente'}
+                  </p>
+                </div>
+              </div>
+            </RadioGroup>
+          </div>
+        )}
+
         {/* Demo Mode Toggle */}
         <DemoModeToggle
           demoMode={settings.demoMode}