feat: Complete high-priority i18n localization with date/time support

This commit implements comprehensive localization for high-priority components:

## Tracking Pages (4 files)
- Localized feeding, sleep, diaper, and medicine tracking pages
- Replaced hardcoded strings with translation keys from tracking namespace
- Added useTranslation hook integration
- All form labels, buttons, and messages now support multiple languages

## Child Dialog Components (2 files)
- Localized ChildDialog (add/edit child form)
- Localized DeleteConfirmDialog
- Added new translation keys to children.json for dialog content
- Includes validation messages and action buttons

## Date/Time Localization (14 files + new hook)
- Created useLocalizedDate hook wrapping date-fns with locale support
- Supports 5 languages: English, Spanish, French, Portuguese, Chinese
- Updated all date formatting across:
  * Tracking pages (feeding, sleep, diaper, medicine)
  * Activity pages (activities, history, track activity)
  * Settings components (sessions, biometric, device trust)
  * Analytics components (insights, growth, sleep chart, feeding graph)
- Date displays automatically adapt to user's language (e.g., "2 hours ago" → "hace 2 horas")

## Translation Updates
- Enhanced children.json with dialog section containing:
  * Form field labels (name, birthDate, gender, photoUrl)
  * Action buttons (add, update, delete, cancel, saving, deleting)
  * Delete confirmation messages
  * Validation error messages

Files changed: 17 files (+164, -113)
Languages supported: en, es, fr, pt-BR, zh-CN

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

maternal-web/components/features/analytics/InsightsDashboard.tsx

@@ -39,7 +39,8 @@ import { useRouter } from 'next/navigation';
 import { motion } from 'framer-motion';
 import { trackingApi, Activity, ActivityType } from '@/lib/api/tracking';
 import { childrenApi, Child } from '@/lib/api/children';
-import { format, subDays, startOfDay, endOfDay, parseISO, differenceInMinutes, formatDistanceToNow } from 'date-fns';
+import { subDays, startOfDay, endOfDay, parseISO, differenceInMinutes } from 'date-fns';
+import { useLocalizedDate } from '@/hooks/useLocalizedDate';
 import { BarChart, Bar, LineChart, Line, PieChart, Pie, Cell, XAxis, YAxis, CartesianGrid, Tooltip, Legend, ResponsiveContainer } from 'recharts';
 
 type DateRange = '7days' | '30days' | '3months';
@@ -97,6 +98,7 @@ const getActivityColor = (type: ActivityType) => {
 
 export const InsightsDashboard: React.FC = () => {
   const router = useRouter();
+  const { format, formatDistanceToNow } = useLocalizedDate();
   const [children, setChildren] = useState<Child[]>([]);
   const [selectedChild, setSelectedChild] = useState<string>('');
   const [dateRange, setDateRange] = useState<DateRange>('7days');