Add builder pattern for MilvusVectorStore

Introduces a fluent builder API to improve configuration readability and
type safety when creating MilvusVectorStore instances. This replaces the
existing configuration object approach which was less intuitive and harder
to maintain.

The builder pattern provides better encapsulation of configuration logic
and validation, while maintaining backward compatibility through a
deprecated config class. This change makes the codebase more maintainable
and the API more discoverable for users.

Key changes:
- Replace configuration object with fluent builder pattern
- Move Milvus-related classes to dedicated milvus package
- Deprecate MilvusVectorStoreConfig in favor of builder
- Update constructor to use builder internally
- Maintain backward compatibility with deprecated config
- Add comprehensive builder methods with validation

spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/vectorstore/milvus/MilvusVectorStoreAutoConfiguration.java

@@ -27,8 +27,8 @@
 import org.springframework.ai.embedding.BatchingStrategy;
 import org.springframework.ai.embedding.EmbeddingModel;
 import org.springframework.ai.embedding.TokenCountBatchingStrategy;
-import org.springframework.ai.vectorstore.MilvusVectorStore;
-import org.springframework.ai.vectorstore.MilvusVectorStore.MilvusVectorStoreConfig;
+import org.springframework.ai.milvus.vectorstore.MilvusVectorStore;
+import org.springframework.ai.milvus.vectorstore.MilvusVectorStore.MilvusVectorStoreConfig;
 import org.springframework.ai.vectorstore.observation.VectorStoreObservationConvention;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
@@ -71,23 +71,14 @@ public MilvusVectorStore vectorStore(MilvusServiceClient milvusClient, Embedding
 			ObjectProvider<ObservationRegistry> observationRegistry,
 			ObjectProvider<VectorStoreObservationConvention> customObservationConvention) {
 
-		MilvusVectorStoreConfig config = MilvusVectorStoreConfig.builder()
-			.withCollectionName(properties.getCollectionName())
-			.withDatabaseName(properties.getDatabaseName())
-			.withIndexType(IndexType.valueOf(properties.getIndexType().name()))
-			.withMetricType(MetricType.valueOf(properties.getMetricType().name()))
-			.withIndexParameters(properties.getIndexParameters())
-			.withEmbeddingDimension(properties.getEmbeddingDimension())
-			.withIDFieldName(properties.getIdFieldName())
-			.withAutoId(properties.isAutoId())
-			.withContentFieldName(properties.getContentFieldName())
-			.withMetadataFieldName(properties.getMetadataFieldName())
-			.withEmbeddingFieldName(properties.getEmbeddingFieldName())
+		return MilvusVectorStore.builder()
+			.milvusClient(milvusClient)
+			.embeddingModel(embeddingModel)
+			.initializeSchema(properties.isInitializeSchema())
+			.batchingStrategy(batchingStrategy)
+			.observationRegistry(observationRegistry.getIfUnique(() -> ObservationRegistry.NOOP))
+			.customObservationConvention(customObservationConvention.getIfAvailable(() -> null))
 			.build();
-
-		return new MilvusVectorStore(milvusClient, embeddingModel, config, properties.isInitializeSchema(),
-				batchingStrategy, observationRegistry.getIfUnique(() -> ObservationRegistry.NOOP),
-				customObservationConvention.getIfAvailable(() -> null));
 	}
 
 	@Bean

spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/vectorstore/milvus/MilvusVectorStoreProperties.java

@@ -17,7 +17,7 @@
 package org.springframework.ai.autoconfigure.vectorstore.milvus;
 
 import org.springframework.ai.autoconfigure.vectorstore.CommonVectorStoreProperties;
-import org.springframework.ai.vectorstore.MilvusVectorStore;
+import org.springframework.ai.milvus.vectorstore.MilvusVectorStore;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.util.Assert;
 

vector-stores/spring-ai-milvus-store/src/main/java/org/springframework/ai/vectorstore/MilvusFilterExpressionConverter.java → vector-stores/spring-ai-milvus-store/src/main/java/org/springframework/ai/milvus/vectorstore/MilvusFilterExpressionConverter.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.ai.vectorstore;
+package org.springframework.ai.milvus.vectorstore;
 
 import org.springframework.ai.vectorstore.filter.Filter.Expression;
 import org.springframework.ai.vectorstore.filter.Filter.ExpressionType;