feat: Implement comprehensive error handling and production deployment pipeline

## Error Handling System
- Add centralized error handling utilities (errorHandler.ts)
- Create reusable error components (ErrorMessage, ErrorToast)
- Implement multilingual error support (preserves backend error messages in 5 languages)
- Update 15+ forms and components with consistent error handling
  - Auth forms: login, register, forgot-password
  - Family management: family page, join family dialog
  - Child management: child dialog
  - All tracking forms: feeding, sleep, diaper, medicine, growth, activity

## Production Build Fixes
- Fix backend TypeScript errors: InviteCode.uses → InviteCode.useCount (5 instances)
- Remove non-existent savedFamily variable from registration response
- Fix admin panel TypeScript errors: SimpleMDE toolbar type, PieChart label type

## User Experience Improvements
- Auto-uppercase invite code and share code inputs
- Visual feedback for case conversion with helper text
- Improved form validation with error codes

## CI/CD Pipeline
- Create comprehensive production deployment checklist (PRODUCTION_DEPLOYMENT_CHECKLIST.md)
- Add automated pre-deployment check script (pre-deploy-check.sh)
  - Validates frontend, backend, and admin panel builds
  - Checks git status, branch, and sync state
  - Verifies environment files and migrations
- Add quick start deployment guide (DEPLOYMENT_QUICK_START.md)
- Add production deployment automation template (deploy-production.sh)

## Cleanup
- Remove outdated push notifications documentation files
- Remove outdated PWA implementation plan

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

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

maternal-web/components/common/ErrorToast.tsx

@@ -0,0 +1,80 @@
+'use client';
+
+import React from 'react';
+import { Snackbar, Alert, AlertTitle } from '@mui/material';
+import { extractError } from '@/lib/utils/errorHandler';
+
+export interface ErrorToastProps {
+  error: any;
+  open: boolean;
+  onClose: () => void;
+  autoHideDuration?: number;
+  showErrorCode?: boolean;
+}
+
+/**
+ * ErrorToast Component
+ * Displays error messages as a toast notification
+ * Preserves backend multilingual error messages
+ */
+export function ErrorToast({
+  error,
+  open,
+  onClose,
+  autoHideDuration = 6000,
+  showErrorCode = false,
+}: ErrorToastProps) {
+  if (!error) {
+    return null;
+  }
+
+  const extracted = extractError(error);
+
+  return (
+    <Snackbar
+      open={open}
+      autoHideDuration={autoHideDuration}
+      onClose={onClose}
+      anchorOrigin={{ vertical: 'top', horizontal: 'right' }}
+    >
+      <Alert onClose={onClose} severity="error" variant="filled" sx={{ width: '100%' }}>
+        {showErrorCode && extracted.code && (
+          <AlertTitle>{extracted.code}</AlertTitle>
+        )}
+        {extracted.message}
+      </Alert>
+    </Snackbar>
+  );
+}
+
+/**
+ * Hook to manage error toast state
+ */
+export function useErrorToast() {
+  const [error, setError] = React.useState<any>(null);
+  const [open, setOpen] = React.useState(false);
+
+  const showError = (err: any) => {
+    setError(err);
+    setOpen(true);
+  };
+
+  const hideError = () => {
+    setOpen(false);
+  };
+
+  const handleClose = (_event?: React.SyntheticEvent | Event, reason?: string) => {
+    if (reason === 'clickaway') {
+      return;
+    }
+    hideError();
+  };
+
+  return {
+    error,
+    open,
+    showError,
+    hideError,
+    handleClose,
+  };
+}