ci: use Maven wrapper instead of mvn to fix command not found on Gitea runner

.gitea/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      # 2. Set up Java and Maven (includes Maven, no separate install needed)
+      # 2. Set up Java (Maven wrapper handles Maven version automatically)
       - name: Set up JDK (Eclipse Temurin)
         uses: actions/setup-java@v4
         with:
@@ -22,9 +22,9 @@ jobs:
           java-version: "17"
           cache: maven
 
-      # 3. Build the Spring Boot application
+      # 3. Build the Spring Boot application using the Maven wrapper
       - name: Build Spring Boot Application
-        run: mvn clean package -DskipTests
+        run: ./mvnw clean package -DskipTests
 
       # 4. Set up Docker Buildx (enables layer caching)
       - name: Set up Docker Buildx