Refactor repository layer using Jakarta Data

Replaced custom repository logic with Jakarta Data interfaces to reduce boilerplate and enhance compile-time query validation. Removed `AbstractRepository` and introduced `TransactionRunner` for consistent transactional support. Updated all repository facades to delegate query operations to generated interfaces while retaining the same API, ensuring backward compatibility. Added dependencies for `jakarta.data-api` and Hibernate's `hibernate-processor` for annotation-based query generation. Verified functional parity and improved testability across the repository layer.

pom.xml

@@ -30,6 +30,22 @@
         </resources>
 
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.14.1</version>
+                <configuration>
+                    <release>${java.version}</release>
+                    <proc>full</proc>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>org.hibernate.orm</groupId>
+                            <artifactId>hibernate-processor</artifactId>
+                            <version>7.1.9.Final</version>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
@@ -176,6 +192,11 @@
             <artifactId>hibernate-hikaricp</artifactId>
             <version>7.1.9.Final</version>
         </dependency>
+        <dependency>
+            <groupId>jakarta.data</groupId>
+            <artifactId>jakarta.data-api</artifactId>
+            <version>1.0.1</version>
+        </dependency>
         <dependency>
             <groupId>com.mysql</groupId>
             <artifactId>mysql-connector-j</artifactId>