feat: add createdAt field to Todo entity and update database migration script

backend/pom.xml

@@ -1,30 +1,31 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
 		<version>4.0.3</version>
-		<relativePath/> <!-- lookup parent from repository -->
+		<relativePath /> <!-- lookup parent from repository -->
 	</parent>
 	<groupId>com.example</groupId>
 	<artifactId>backend</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
 	<name>backend</name>
 	<description>Demo project for Spring Boot</description>
-	<url/>
+	<url />
 	<licenses>
-		<license/>
+		<license />
 	</licenses>
 	<developers>
-		<developer/>
+		<developer />
 	</developers>
 	<scm>
-		<connection/>
-		<developerConnection/>
-		<tag/>
-		<url/>
+		<connection />
+		<developerConnection />
+		<tag />
+		<url />
 	</scm>
 	<properties>
 		<java.version>25</java.version>
@@ -68,9 +69,20 @@
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-actuator</artifactId>
-		</dependency>		
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-flyway</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.flywaydb</groupId>
+			<artifactId>flyway-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.flywaydb</groupId>
+			<artifactId>flyway-database-postgresql</artifactId>
+		</dependency>
 	</dependencies>
-
 	<build>
 		<plugins>
 			<plugin>
@@ -80,4 +92,4 @@
 		</plugins>
 	</build>
 
-</project>
+</project>