refactor: Harden detekt setup, address some issues (#507)

# Detekt setup hardeing; address some issues

- Address some detekt findings: missing KDocs, formatting, use `check*`
& `orEmpty()``
- Remove unnecessary KDoc comments from deprecated classes in `types.kt`
- Add Detekt baseline XML files for all modules
- Enforce stricter Detekt rules by setting `failOnSeverity` from `None`
to `Error`

## Motivation and Context

Detekt is not actually failing the build on violations. This PR is
enabling Detekt to fail on errors. Baseline fines added for historical
issues. Follow-up for #501

## How Has This Been Tested?
Regressions

## Breaking Changes

No breaking changes.

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] Refactoring
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

conformance-test/detekt-baseline.xml

@@ -0,0 +1,9 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<SmellBaseline>
+  <ManuallySuppressedIssues/>
+  <CurrentIssues>
+    <ID>BracesOnWhenStatements:ConformanceServer.kt:HttpServerTransport$when</ID>
+    <ID>BracesOnWhenStatements:ConformanceTest.kt:ConformanceTest$when</ID>
+    <ID>ForbiddenComment:ConformanceTest.kt:ConformanceTest.Companion$// TODO: Fix</ID>
+  </CurrentIssues>
+</SmellBaseline>

conformance-test/src/test/kotlin/io/modelcontextprotocol/kotlin/sdk/conformance/ConformanceServer.kt

@@ -73,6 +73,7 @@ private const val MESSAGE_QUEUE_CAPACITY = 256
 private fun isInitializeRequest(json: JsonElement): Boolean =
     json is JsonObject && json["method"]?.jsonPrimitive?.contentOrNull == "initialize"
 
+@Suppress("CyclomaticComplexMethod", "LongMethod")
 fun main(args: Array<String>) {
     val port = args.getOrNull(0)?.toIntOrNull() ?: 3000
 
@@ -236,6 +237,7 @@ fun main(args: Array<String>) {
     }.start(wait = true)
 }
 
+@Suppress("LongMethod")
 private fun createConformanceServer(): Server {
     val server = Server(
         Implementation(
@@ -371,7 +373,9 @@ private class HttpServerTransport(private val sessionId: String) : AbstractTrans
                     }
                 }
 
-                else -> call.respond(HttpStatusCode.Accepted)
+                else -> {
+                    call.respond(HttpStatusCode.Accepted)
+                }
             }
         } catch (e: CancellationException) {
             throw e

conformance-test/src/test/kotlin/io/modelcontextprotocol/kotlin/sdk/conformance/ConformanceTest.kt

@@ -17,6 +17,7 @@ import java.net.URI
 import java.util.concurrent.TimeUnit
 import kotlin.io.path.createTempFile
 import kotlin.properties.Delegates
+import kotlin.test.fail
 
 private val logger = KotlinLogging.logger {}
 
@@ -320,7 +321,8 @@ class ConformanceTest {
             }
             process.destroyForcibly()
             throw AssertionError(
-                "❌ $capitalizedType conformance test [$transportType] '$scenario' timed out after $timeoutSeconds seconds",
+                "❌ $capitalizedType conformance test [$transportType] '$scenario' " +
+                    "timed out after $timeoutSeconds seconds",
             )
         }
 
@@ -331,8 +333,9 @@ class ConformanceTest {
                 logger.error {
                     "$capitalizedType conformance test [$transportType] '$scenario' failed with exit code: $exitCode"
                 }
-                throw AssertionError(
-                    "❌ $capitalizedType conformance test [$transportType] '$scenario' failed (exit code: $exitCode). Check test output above for details.",
+                fail(
+                    "❌ $capitalizedType conformance test [$transportType] '$scenario' " +
+                        "failed (exit code: $exitCode). Check test output above for details.",
                 )
             }
         }

conformance-test/src/test/kotlin/io/modelcontextprotocol/kotlin/sdk/conformance/WebSocketConformanceClient.kt

@@ -24,6 +24,7 @@ class WebSocketClientTransport(override val session: WebSocketSession) : WebSock
     }
 }
 
+@Suppress("LongMethod")
 fun main(args: Array<String>) {
     require(args.isNotEmpty()) {
         "Server WebSocket URL must be provided as an argument"