feat: Implement backend API and basic frontend structure

Adds initial backend API endpoints for fetching users and attendances, including basic filtering. Sets up the frontend routing with a layout component and includes placeholder pages for dashboard, users, and login. Refactors the README for local development setup.

components/DateRangePicker.tsx

@@ -0,0 +1,49 @@
+import React from 'react';
+import { Calendar } from 'lucide-react';
+import { DateRange } from '../types';
+
+interface DateRangePickerProps {
+  dateRange: DateRange;
+  onChange: (range: DateRange) => void;
+}
+
+export const DateRangePicker: React.FC<DateRangePickerProps> = ({ dateRange, onChange }) => {
+  const formatDateForInput = (date: Date) => {
+    return date.toISOString().split('T')[0];
+  };
+
+  const handleStartChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const newStart = new Date(e.target.value);
+    if (!isNaN(newStart.getTime())) {
+      onChange({ ...dateRange, start: newStart });
+    }
+  };
+
+  const handleEndChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const newEnd = new Date(e.target.value);
+    if (!isNaN(newEnd.getTime())) {
+      onChange({ ...dateRange, end: newEnd });
+    }
+  };
+
+  return (
+    <div className="flex items-center gap-2 bg-white border border-slate-200 px-3 py-2 rounded-lg shadow-sm hover:border-slate-300 transition-colors">
+      <Calendar size={16} className="text-slate-500 shrink-0" />
+      <div className="flex items-center gap-2 text-sm">
+        <input
+          type="date"
+          value={formatDateForInput(dateRange.start)}
+          onChange={handleStartChange}
+          className="bg-transparent text-slate-700 font-medium outline-none cursor-pointer w-28 md:w-auto"
+        />
+        <span className="text-slate-400">até</span>
+        <input
+          type="date"
+          value={formatDateForInput(dateRange.end)}
+          onChange={handleEndChange}
+          className="bg-transparent text-slate-700 font-medium outline-none cursor-pointer w-28 md:w-auto"
+        />
+      </div>
+    </div>
+  );
+};