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/settings/BiometricSettings.tsx

@@ -33,9 +33,10 @@ import {
 import { biometricApi, type BiometricCredential } from '@/lib/api/biometric';
 import { startRegistration } from '@simplewebauthn/browser';
 import { motion } from 'framer-motion';
-import { formatDistanceToNow } from 'date-fns';
+import { useLocalizedDate } from '@/hooks/useLocalizedDate';
 
 export function BiometricSettings() {
+  const { formatDistanceToNow } = useLocalizedDate();
   const [credentials, setCredentials] = useState<BiometricCredential[]>([]);
   const [isLoading, setIsLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);

maternal-web/components/settings/DeviceTrustManagement.tsx

@@ -35,9 +35,10 @@ import {
 } from '@mui/icons-material';
 import { devicesApi, type DeviceInfo } from '@/lib/api/devices';
 import { motion } from 'framer-motion';
-import { formatDistanceToNow } from 'date-fns';
+import { useLocalizedDate } from '@/hooks/useLocalizedDate';
 
 export function DeviceTrustManagement() {
+  const { formatDistanceToNow } = useLocalizedDate();
   const [devices, setDevices] = useState<DeviceInfo[]>([]);
   const [isLoading, setIsLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);

maternal-web/components/settings/SessionsManagement.tsx

@@ -31,9 +31,10 @@ import {
 } from '@mui/icons-material';
 import { sessionsApi, type SessionInfo } from '@/lib/api/sessions';
 import { motion } from 'framer-motion';
-import { formatDistanceToNow } from 'date-fns';
+import { useLocalizedDate } from '@/hooks/useLocalizedDate';
 
 export function SessionsManagement() {
+  const { formatDistanceToNow } = useLocalizedDate();
   const [sessions, setSessions] = useState<SessionInfo[]>([]);
   const [isLoading, setIsLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);