feat: Apply localization to Login, Dashboard, and Navigation (Phase 9 - Batch 1)

**Pages Localized:**
- Login page: All UI strings (titles, labels, buttons, links)
- Dashboard page: Welcome message, quick actions, daily summary, predictions
- AppShell: Connection status and presence indicators
- MobileNav: Menu items and app branding
- TabBar: Bottom navigation labels

**Translation Files:**
- Created dashboard.json for all 5 languages (en, es, fr, pt, zh)
- Enhanced common.json with navigation and connection strings
- Updated i18n config to include dashboard namespace

**Languages Supported:**
- English, Spanish, French, Portuguese, Chinese (Simplified)

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

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

maternal-web/app/(auth)/login/page.tsx

@@ -26,6 +26,7 @@ import { tokenStorage } from '@/lib/utils/tokenStorage';
 import { biometricApi } from '@/lib/api/biometric';
 import { startAuthentication } from '@simplewebauthn/browser';
 import Link from 'next/link';
+import { useTranslation } from '@/hooks/useTranslation';
 
 const loginSchema = z.object({
   email: z.string().email('Invalid email address'),
@@ -35,6 +36,7 @@ const loginSchema = z.object({
 type LoginFormData = z.infer<typeof loginSchema>;
 
 export default function LoginPage() {
+  const { t } = useTranslation('auth');
   const [showPassword, setShowPassword] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [isLoading, setIsLoading] = useState(false);
@@ -178,7 +180,7 @@ export default function LoginPage() {
             fontWeight="600"
             color="primary.main"
           >
-            Welcome Back 👋
+            {t('login.title')}
           </Typography>
           <Typography
             variant="body2"
@@ -186,7 +188,7 @@ export default function LoginPage() {
             color="text.secondary"
             sx={{ mb: 3 }}
           >
-            Sign in to continue tracking your child's journey
+            {t('login.subtitle')}
           </Typography>
 
           {error && (
@@ -198,7 +200,7 @@ export default function LoginPage() {
           <Box component="form" onSubmit={handleSubmit(onSubmit)}>
             <TextField
               fullWidth
-              label="Email"
+              label={t('login.email')}
               type="email"
               margin="normal"
               error={!!errors.email}
@@ -213,7 +215,7 @@ export default function LoginPage() {
 
             <TextField
               fullWidth
-              label="Password"
+              label={t('login.password')}
               type={showPassword ? 'text' : 'password'}
               margin="normal"
               error={!!errors.password}
@@ -245,7 +247,7 @@ export default function LoginPage() {
                 variant="body2"
                 sx={{ cursor: 'pointer', textDecoration: 'none' }}
               >
-                Forgot password?
+                {t('login.forgotPassword')}
               </MuiLink>
             </Box>
 
@@ -260,14 +262,14 @@ export default function LoginPage() {
               {isLoading ? (
                 <CircularProgress size={24} color="inherit" />
               ) : (
-                'Sign In'
+                t('login.submit')
               )}
             </Button>
           </Box>
 
           <Divider sx={{ my: 3 }}>
             <Typography variant="body2" color="text.secondary">
-              OR
+              {t('login.or')}
             </Typography>
           </Divider>
 
@@ -279,7 +281,7 @@ export default function LoginPage() {
             disabled={isLoading}
             sx={{ mb: 2 }}
           >
-            Continue with Google
+            {t('login.continueWithGoogle')}
           </Button>
 
           <Button
@@ -289,7 +291,7 @@ export default function LoginPage() {
             size="large"
             disabled={isLoading}
           >
-            Continue with Apple
+            {t('login.continueWithApple')}
           </Button>
 
           {isBiometricSupported && (
@@ -302,16 +304,16 @@ export default function LoginPage() {
               onClick={handleBiometricLogin}
               sx={{ mt: 2 }}
             >
-              {isBiometricLoading ? 'Authenticating...' : 'Sign in with Biometrics'}
+              {isBiometricLoading ? t('login.biometric.authenticating') : t('login.biometric.useFaceId')}
             </Button>
           )}
 
           <Box sx={{ mt: 3, textAlign: 'center' }}>
             <Typography variant="body2" color="text.secondary">
-              Don't have an account?{' '}
+              {t('login.noAccount')}{' '}
               <Link href="/register" passHref legacyBehavior>
                 <MuiLink sx={{ cursor: 'pointer', fontWeight: 600 }}>
-                  Sign up
+                  {t('login.signUp')}
                 </MuiLink>
               </Link>
             </Typography>