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/children/DeleteConfirmDialog.tsx

@@ -9,6 +9,7 @@ import {
   Typography,
 } from '@mui/material';
 import { Warning } from '@mui/icons-material';
+import { useTranslation } from '@/hooks/useTranslation';
 
 interface DeleteConfirmDialogProps {
   open: boolean;
@@ -25,6 +26,8 @@ export function DeleteConfirmDialog({
   childName,
   isLoading = false,
 }: DeleteConfirmDialogProps) {
+  const { t } = useTranslation('children');
+
   return (
     <Dialog
       open={open}
@@ -37,22 +40,22 @@ export function DeleteConfirmDialog({
     >
       <DialogTitle id="delete-dialog-title" sx={{ display: 'flex', alignItems: 'center', gap: 1 }}>
         <Warning color="warning" aria-hidden="true" />
-        Confirm Delete
+        {t('dialog.confirmDelete')}
       </DialogTitle>
       <DialogContent>
         <Typography variant="body1" id="delete-dialog-description">
-          Are you sure you want to delete <strong>{childName}</strong>?
+          {t('dialog.confirmDeleteMessage')} <strong>{childName}</strong>?
         </Typography>
         <Typography variant="body2" color="text.secondary" sx={{ mt: 2 }}>
-          This action cannot be undone. All associated data will be permanently removed.
+          {t('dialog.confirmDeleteWarning')}
         </Typography>
       </DialogContent>
       <DialogActions>
         <Button onClick={onClose} disabled={isLoading}>
-          Cancel
+          {t('dialog.cancel')}
         </Button>
         <Button onClick={onConfirm} color="error" variant="contained" disabled={isLoading}>
-          {isLoading ? 'Deleting...' : 'Delete'}
+          {isLoading ? t('dialog.deleting') : t('dialog.delete')}
         </Button>
       </DialogActions>
     </Dialog>