fix: resolve typescript compilation errors

src/components/DateRangePicker.tsx

@@ -43,7 +43,7 @@ const DateRangePicker: React.FC<DateRangePickerProps> = ({ dateRange, onChange }
     }
   };
 
-  const openPicker = (ref: React.RefObject<HTMLInputElement>) => {
+  const openPicker = (ref: React.RefObject<HTMLInputElement | null>) => {
     if (ref.current) {
       try {
         if ('showPicker' in HTMLInputElement.prototype) {

src/pages/ClientDetails.tsx

@@ -1,6 +1,6 @@
 import { useMemo } from 'react';
 import { useParams, Link, useOutletContext } from 'react-router-dom';
-import { ArrowLeft, User, Calendar, Tag, Package, DollarSign } from 'lucide-react';
+import { ArrowLeft, User, Tag, Package, DollarSign } from 'lucide-react';
 import type { OrderData } from '../types';
 
 const ClientDetails = () => {

src/pages/ProductDetails.tsx

@@ -1,6 +1,6 @@
 import { useMemo } from 'react';
 import { useParams, Link, useOutletContext } from 'react-router-dom';
-import { ArrowLeft, Package, DollarSign, Calendar } from 'lucide-react';
+import { ArrowLeft, Package, DollarSign } from 'lucide-react';
 import { BarChart, Bar, XAxis, YAxis, CartesianGrid, Tooltip, ResponsiveContainer } from 'recharts';
 import DateRangePicker from '../components/DateRangePicker';
 import type { OrderData, DateRange } from '../types';

src/pages/Products.tsx

@@ -1,6 +1,6 @@
 import { useMemo, useState } from 'react';
 import { Link, useOutletContext } from 'react-router-dom';
-import { Search, ChevronRight, Package, TrendingUp } from 'lucide-react';
+import { Search, Package, TrendingUp } from 'lucide-react';
 import DateRangePicker from '../components/DateRangePicker';
 import type { OrderData, DateRange } from '../types';