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/ChildDialog.tsx

@@ -13,6 +13,7 @@ import {
   Alert,
 } from '@mui/material';
 import { Child, CreateChildData } from '@/lib/api/children';
+import { useTranslation } from '@/hooks/useTranslation';
 
 interface ChildDialogProps {
   open: boolean;
@@ -23,6 +24,7 @@ interface ChildDialogProps {
 }
 
 export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false }: ChildDialogProps) {
+  const { t } = useTranslation('children');
   const [formData, setFormData] = useState<CreateChildData>({
     name: '',
     birthDate: '',
@@ -61,11 +63,11 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
 
     // Validation
     if (!formData.name.trim()) {
-      setError('Please enter a name');
+      setError(t('dialog.validation.nameRequired'));
       return;
     }
     if (!formData.birthDate) {
-      setError('Please select a birth date');
+      setError(t('dialog.validation.birthDateRequired'));
       return;
     }
 
@@ -74,7 +76,7 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
     const today = new Date();
     today.setHours(0, 0, 0, 0);
     if (selectedDate > today) {
-      setError('Birth date cannot be in the future');
+      setError(t('dialog.validation.birthDateFuture'));
       return;
     }
 
@@ -82,7 +84,7 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
       await onSubmit(formData);
       onClose();
     } catch (err: any) {
-      setError(err.message || 'Failed to save child');
+      setError(err.message || t('errors.saveFailed'));
     }
   };
 
@@ -95,7 +97,7 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
       aria-labelledby="child-dialog-title"
       aria-describedby="child-dialog-description"
     >
-      <DialogTitle id="child-dialog-title">{child ? 'Edit Child' : 'Add Child'}</DialogTitle>
+      <DialogTitle id="child-dialog-title">{child ? t('editChild') : t('addChild')}</DialogTitle>
       <DialogContent>
         <Box
           id="child-dialog-description"
@@ -108,7 +110,7 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
           )}
 
           <TextField
-            label="Name"
+            label={t('dialog.name')}
             value={formData.name}
             onChange={handleChange('name')}
             fullWidth
@@ -118,7 +120,7 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
           />
 
           <TextField
-            label="Birth Date"
+            label={t('dialog.birthDate')}
             type="date"
             value={formData.birthDate}
             onChange={handleChange('birthDate')}
@@ -131,7 +133,7 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
           />
 
           <TextField
-            label="Gender"
+            label={t('dialog.gender')}
             value={formData.gender}
             onChange={handleChange('gender')}
             fullWidth
@@ -139,27 +141,27 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
             select
             disabled={isLoading}
           >
-            <MenuItem value="male">Male</MenuItem>
-            <MenuItem value="female">Female</MenuItem>
-            <MenuItem value="other">Other</MenuItem>
+            <MenuItem value="male">{t('gender.male')}</MenuItem>
+            <MenuItem value="female">{t('gender.female')}</MenuItem>
+            <MenuItem value="other">{t('gender.other')}</MenuItem>
           </TextField>
 
           <TextField
-            label="Photo URL (Optional)"
+            label={t('dialog.photoUrl')}
             value={formData.photoUrl}
             onChange={handleChange('photoUrl')}
             fullWidth
-            placeholder="https://example.com/photo.jpg"
+            placeholder={t('dialog.photoPlaceholder')}
             disabled={isLoading}
           />
         </Box>
       </DialogContent>
       <DialogActions>
         <Button onClick={onClose} disabled={isLoading}>
-          Cancel
+          {t('dialog.cancel')}
         </Button>
         <Button onClick={handleSubmit} variant="contained" disabled={isLoading}>
-          {isLoading ? 'Saving...' : child ? 'Update' : 'Add'}
+          {isLoading ? t('dialog.saving') : child ? t('dialog.update') : t('dialog.add')}
         </Button>
       </DialogActions>
     </Dialog>