refactor(dsl)!: mark constructors in DSL builders as internal to restrict visibility

Author: kpavlov

kotlin-sdk-core/api/kotlin-sdk-core.api

@@ -3675,6 +3675,7 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/RequestMeta$Companio
 }
 
 public final class io/modelcontextprotocol/kotlin/sdk/types/RequestMetaBuilder {
+	public fun <init> ()V
 	public final fun progressToken (I)V
 	public final fun progressToken (J)V
 	public final fun progressToken (Ljava/lang/String;)V

kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/content.dsl.kt

@@ -21,7 +21,7 @@ import kotlinx.serialization.json.buildJsonObject
  * @see AudioContentBuilder
  */
 @McpDsl
-public abstract class MediaContentBuilder {
+public abstract class MediaContentBuilder @PublishedApi internal constructor() {
     protected var annotations: Annotations? = null
     protected var meta: JsonObject? = null
 

kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/request.dsl.kt

@@ -21,7 +21,7 @@ import kotlinx.serialization.json.buildJsonObject
  * @see PaginatedRequestBuilder
  */
 @McpDsl
-public abstract class RequestBuilder {
+public abstract class RequestBuilder @PublishedApi internal constructor() {
     protected var meta: RequestMeta? = null
 
     /**
@@ -73,7 +73,7 @@ public abstract class RequestBuilder {
  * @see RequestBuilder.meta
  */
 @McpDsl
-public class RequestMetaBuilder internal constructor() {
+public class RequestMetaBuilder @PublishedApi internal constructor() {
     private val content: MutableMap<String, JsonElement> = linkedMapOf()
 
     /**
@@ -196,7 +196,7 @@ public class RequestMetaBuilder internal constructor() {
  * @see RequestBuilder
  */
 @McpDsl
-public abstract class PaginatedRequestBuilder : RequestBuilder() {
+public abstract class PaginatedRequestBuilder @PublishedApi internal constructor() : RequestBuilder() {
     /**
      * Optional pagination cursor for fetching the next page of results.
      *

kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/result.dsl.kt

@@ -16,7 +16,7 @@ import kotlinx.serialization.json.buildJsonObject
  * @see ServerResult
  */
 @McpDsl
-public abstract class ResultBuilder {
+public abstract class ResultBuilder @PublishedApi internal constructor() {
     protected var meta: JsonObject? = null
 
     /**
@@ -78,7 +78,7 @@ public abstract class ResultBuilder {
  * @see PaginatedResult
  */
 @McpDsl
-public abstract class PaginatedResultBuilder : ResultBuilder() {
+public abstract class PaginatedResultBuilder @PublishedApi internal constructor() : ResultBuilder() {
     /**
      * Optional pagination cursor for fetching the next page of results.
      *