feat: 8 AI providers, rich text editor, agent notifications, UI contrast & font settings

- Add DeepSeek, OpenRouter, Mistral, Z.AI, LM Studio as AI providers
  with editable model names via Combobox in admin settings
- Fix OpenRouter broken by normalizeProvider bug in config.ts
- Convert agent-created notes from Markdown to HTML (TipTap rich text)
- Add Notification model + in-app notifications for agent results
- Agent notification click opens the created note directly
- Add note count display on notebook and inbox headers
- Fix checklist toggle in card view (persist state via localCheckItems)
- Add checklist creation option in tabs/list view (dropdown on + button)
- Fix image description ENOENT error with HTTP fallback
- Improve UI contrast across all themes (input, border, checkbox visibility)
- Add font family setting (Inter vs System Default) in Appearance settings
- Fix CSS font-sans variable conflict (removed dead Geist references)
- Update README with new features and 8 providers

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

memento-note/app/(main)/settings/appearance/appearance-settings-client.tsx

@@ -12,14 +12,16 @@ interface AppearanceSettingsClientProps {
   initialTheme: string
   initialNotesViewMode: 'masonry' | 'tabs'
   initialCardSizeMode?: 'variable' | 'uniform'
+  initialFontFamily?: string
 }
 
-export function AppearanceSettingsClient({ initialFontSize, initialTheme, initialNotesViewMode, initialCardSizeMode = 'variable' }: AppearanceSettingsClientProps) {
+export function AppearanceSettingsClient({ initialFontSize, initialTheme, initialNotesViewMode, initialCardSizeMode = 'variable', initialFontFamily = 'inter' }: AppearanceSettingsClientProps) {
   const { t } = useLanguage()
   const [theme, setTheme] = useState(initialTheme || 'light')
   const [fontSize, setFontSize] = useState(initialFontSize || 'medium')
   const [notesViewMode, setNotesViewMode] = useState<'masonry' | 'tabs'>(initialNotesViewMode)
   const [cardSizeMode, setCardSizeMode] = useState<'variable' | 'uniform'>(initialCardSizeMode)
+  const [fontFamily, setFontFamily] = useState(initialFontFamily)
 
   const handleThemeChange = async (value: string) => {
     setTheme(value)
@@ -69,6 +71,20 @@ export function AppearanceSettingsClient({ initialFontSize, initialTheme, initia
     toast.success(t('settings.settingsSaved') || 'Saved')
   }
 
+  const handleFontFamilyChange = async (value: string) => {
+    const font = value === 'system' ? 'system' : 'inter'
+    setFontFamily(font)
+    localStorage.setItem('font-family', font)
+    const root = document.documentElement
+    if (font === 'system') {
+      root.classList.add('font-system')
+    } else {
+      root.classList.remove('font-system')
+    }
+    await updateAISettings({ fontFamily: font })
+    toast.success(t('settings.settingsSaved') || 'Saved')
+  }
+
   return (
     <div className="space-y-6">
       <div>
@@ -116,6 +132,23 @@ export function AppearanceSettingsClient({ initialFontSize, initialTheme, initia
         />
       </SettingsSection>
 
+      <SettingsSection
+        title={t('appearance.fontFamilyLabel') || 'Font Family'}
+        icon={<span className="text-2xl">🔤</span>}
+        description={t('appearance.fontFamilyDescription') || 'Choose the font used throughout the app'}
+      >
+        <SettingSelect
+          label={t('appearance.fontFamilyLabel') || 'Font Family'}
+          description={t('appearance.selectFontFamily') || 'Inter is optimized for readability, System uses your OS native font'}
+          value={fontFamily}
+          options={[
+            { value: 'inter', label: 'Inter' },
+            { value: 'system', label: t('appearance.fontSystem') || 'System Default' },
+          ]}
+          onChange={handleFontFamilyChange}
+        />
+      </SettingsSection>
+
       <SettingsSection
         title={t('appearance.notesViewLabel')}
         icon={<span className="text-2xl">📋</span>}

memento-note/app/(main)/settings/appearance/page.tsx

@@ -21,6 +21,7 @@ export default async function AppearanceSettingsPage() {
       initialTheme={userSettings.theme}
       initialNotesViewMode={aiSettings.notesViewMode === 'masonry' ? 'masonry' : 'tabs'}
       initialCardSizeMode={userSettings.cardSizeMode}
+      initialFontFamily={aiSettings.fontFamily || 'inter'}
     />
   )
 }