build: add comprehensive docker files for frontend & backend

Update docker-compose.yml to include new Dockerfiles

src/main/Dockerfile

@@ -0,0 +1,21 @@
+# Build stage
+FROM maven:3.9.6-eclipse-temurin-21 AS builder
+WORKDIR /app
+COPY pom.xml .
+COPY src ./src
+RUN mvn clean package -DskipTests
+
+
+# Run stage
+FROM eclipse-temurin:21-jdk
+
+# dependencies
+RUN apt-get update && \
+    apt-get install -y ffmpeg && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+COPY --from=builder /app/target/*.jar app.jar
+EXPOSE 8080
+ENTRYPOINT ["java", "-jar", "app.jar"]