feat: Add comprehensive error boundaries for graceful error handling

Implemented React error boundaries to catch and handle errors gracefully:

**Core Error Handling Components:**
- Created ErrorBoundary class component with error catching and logging
- Created specialized fallback UIs (MinimalErrorFallback, DataErrorFallback,
  ComponentErrorFallback, FormErrorFallback, ChartErrorFallback, ImageErrorFallback)
- Added withErrorBoundary HOC for easy component wrapping
- Created errorLogger service with Sentry integration placeholder

**Error Logging Service (errorLogger.ts):**
- Centralized error logging with severity levels (FATAL, ERROR, WARNING, INFO, DEBUG)
- Context enrichment (URL, userAgent, timestamp, environment)
- Local storage of last 10 errors in sessionStorage for debugging
- User context management (setUser, clearUser)
- Breadcrumb support for debugging trails

**App Integration:**
- Wrapped root layout with top-level ErrorBoundary for catastrophic errors
- Added NetworkStatusIndicator to main page for offline sync visibility
- Wrapped daily summary section with isolated DataErrorFallback
- Added error boundary to AI assistant page with ComponentErrorFallback
- Wrapped feeding tracking form with FormErrorFallback using withErrorBoundary HOC
- Protected analytics charts with isolated ChartErrorFallback boundaries

**Error Recovery Features:**
- Isolated error boundaries prevent cascade failures
- Retry buttons on all fallback UIs
- Error count tracking with user warnings
- Development-mode error details display
- Automatic error logging to service (when Sentry integrated)

Next: Integration with Sentry for production error tracking

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

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

maternal-web/app/ai-assistant/page.tsx

@@ -4,6 +4,8 @@ import { lazy, Suspense } from 'react';
 import { AppShell } from '@/components/layouts/AppShell/AppShell';
 import { ProtectedRoute } from '@/components/common/ProtectedRoute';
 import { LoadingFallback } from '@/components/common/LoadingFallback';
+import { ErrorBoundary } from '@/components/common/ErrorBoundary';
+import { ComponentErrorFallback } from '@/components/common/ErrorFallbacks';
 
 // Lazy load the AI chat interface component
 const AIChatInterface = lazy(() =>
@@ -16,9 +18,14 @@ export default function AIAssistantPage() {
   return (
     <ProtectedRoute>
       <AppShell>
-        <Suspense fallback={<LoadingFallback variant="chat" />}>
-          <AIChatInterface />
-        </Suspense>
+        <ErrorBoundary
+          isolate
+          fallback={<ComponentErrorFallback error={new Error('AI Assistant failed to load')} />}
+        >
+          <Suspense fallback={<LoadingFallback variant="chat" />}>
+            <AIChatInterface />
+          </Suspense>
+        </ErrorBoundary>
       </AppShell>
     </ProtectedRoute>
   );