Fixed warnings when -require-explicit-sendable is enabled

.gitignore

@@ -8,3 +8,5 @@ DerivedData/
 .netrc
 Package.resolved
 .swiftpm/xcode/
+.vscode
+.swift-version

Package.swift

@@ -5,12 +5,14 @@ import PackageDescription
 let extraSettings: [SwiftSetting] = [
     .enableExperimentalFeature("SuppressedAssociatedTypes"),
     .enableExperimentalFeature("LifetimeDependence"),
+    .enableExperimentalFeature("NonescapableTypes"),
     .enableUpcomingFeature("LifetimeDependence"),
     .enableUpcomingFeature("NonisolatedNonsendingByDefault"),
     .enableUpcomingFeature("InferIsolatedConformances"),
     .enableUpcomingFeature("ExistentialAny"),
     .enableUpcomingFeature("MemberImportVisibility"),
-    .enableUpcomingFeature("InternalImportsByDefault")
+    .enableUpcomingFeature("InternalImportsByDefault"),
+    .unsafeFlags(["-Xfrontend", "-require-explicit-sendable", "-warnings-as-errors"])
 ]
 
 let package = Package(

Sources/HTTPServer/HTTPServer.swift

@@ -62,7 +62,7 @@ import Synchronization
 /// }
 /// ```
 @available(macOS 26.0, iOS 26.0, watchOS 26.0, tvOS 26.0, visionOS 26.0, *)
-public final class Server<RequestHandler: HTTPServerRequestHandler> {
+public final class Server<RequestHandler: HTTPServerRequestHandler>: Sendable {
     /// Starts an HTTP server with a closure-based request handler.
     ///
     /// This method provides a convenient way to start an HTTP server using a closure to handle incoming requests.

Sources/HTTPServer/HTTPServerClosureRequestHandler.swift

@@ -24,7 +24,7 @@ public import HTTPTypes
 /// }
 /// ```
 @available(macOS 26.0, iOS 26.0, watchOS 26.0, tvOS 26.0, visionOS 26.0, *)
-public struct HTTPServerClosureRequestHandler: HTTPServerRequestHandler {
+public struct HTTPServerClosureRequestHandler: HTTPServerRequestHandler, Sendable {
     /// The underlying closure that handles HTTP requests
     private let _handler:
         nonisolated(nonsending) @Sendable (

Sources/Middleware/MiddlewareBuilder.swift

@@ -21,7 +21,7 @@
 /// }
 /// ```
 @resultBuilder
-public struct MiddlewareChainBuilder {
+public struct MiddlewareChainBuilder: Sendable {
     /// Builds a middleware chain from a single middleware component.
     ///
     /// This is the base case for the result builder pattern, handling a single middleware.