feat: add SSE transport and improve documentation

- Add Server-Sent Events (SSE) transport implementation with test coverage
- Add detailed documentation for both SSE and STDIO transports
- Extract common test logic into abstract base classes
- Add testcontainers support for SSE integration tests
- Replace System.out with SLF4J logging
- Externalize dependency versions to properties
- Implement endpoint event handling per MCP spec
- Add message endpoint sink for reliable message routing
- Improve error handling and graceful shutdown
- Update core module README with expanded features and examples
- Add dependency version properties and logging configuration
- Update architecture and class diagrams

Resolves #4

spring-ai-mcp-core/pom.xml

@@ -21,16 +21,35 @@
 	</scm>
 
 	<dependencies>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-api</artifactId>
+			<version>${slf4j-api.version}</version>
+		</dependency>
+
+		<dependency>
+			<groupId>ch.qos.logback</groupId>
+			<artifactId>logback-classic</artifactId>
+			<version>${logback.version}</version>
+		</dependency>
+
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-databind</artifactId>
-			<version>2.18.2</version>
+			<version>${jackson.version}</version>
 		</dependency>
+
 		<dependency>
 			<groupId>io.projectreactor</groupId>
 			<artifactId>reactor-core</artifactId>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webflux</artifactId>
+			<version>${springframework.version}</version>
+		</dependency>
+
 		<dependency>
 			<groupId>org.assertj</groupId>
 			<artifactId>assertj-core</artifactId>
@@ -54,8 +73,14 @@
 			<artifactId>reactor-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>junit-jupiter</artifactId>
+			<version>${testcontainers.version}</version>
+			<scope>test</scope>
+		</dependency>
 
 	</dependencies>
 
 
-</project>
+</project>