feat: Add advanced analytics UI components in frontend

- Add comprehensive API client methods for all advanced analytics endpoints
- Create CircadianRhythmCard component for sleep pattern visualization
- Create AnomalyAlertsPanel for anomaly detection and alerts
- Create GrowthPercentileChart with WHO/CDC percentiles
- Create CorrelationInsights for activity correlations
- Create TrendAnalysisChart with predictions
- Add advanced analytics page with all new components
- Add UI component library (shadcn/ui) setup
- Add navigation link to advanced analytics from insights page

All advanced analytics features are now accessible from the frontend UI.

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

@@ -14,6 +14,7 @@ import {
   Alert,
   Grid,
   IconButton,
+  Button,
 } from '@mui/material';
 import { Timeline, TrendingUp, Assessment, ArrowBack } from '@mui/icons-material';
 import { useRouter } from 'next/navigation';
@@ -170,18 +171,28 @@ export function UnifiedInsightsDashboard() {
     >
       <Box sx={{ px: { xs: 2, sm: 3 }, py: 3 }}>
         {/* Header with Back Button */}
-        <Box sx={{ display: 'flex', alignItems: 'center', mb: 3 }}>
-          <IconButton onClick={() => router.back()} sx={{ mr: 2 }}>
-            <ArrowBack />
-          </IconButton>
-          <Box>
-            <Typography variant="h4" fontWeight={600}>
-              Insights & Predictions
-            </Typography>
-            <Typography variant="body2" color="text.secondary">
-              AI-powered insights, patterns, and predictions for your child
-            </Typography>
+        <Box sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', mb: 3 }}>
+          <Box sx={{ display: 'flex', alignItems: 'center' }}>
+            <IconButton onClick={() => router.back()} sx={{ mr: 2 }}>
+              <ArrowBack />
+            </IconButton>
+            <Box>
+              <Typography variant="h4" fontWeight={600}>
+                Insights & Predictions
+              </Typography>
+              <Typography variant="body2" color="text.secondary">
+                AI-powered insights, patterns, and predictions for your child
+              </Typography>
+            </Box>
           </Box>
+          <Button
+            variant="outlined"
+            color="primary"
+            onClick={() => router.push('/analytics/advanced')}
+            startIcon={<TrendingUp />}
+          >
+            Advanced Analytics
+          </Button>
         </Box>
 
         {/* Error Alert */}