feat(network): support custom relay servers

Add strict custom Iroh relay profiles with safe restart and rollback across the Rust core, Compose apps, and Apple apps. Preserve multi-relay invitations and fail closed on configuration or recovery mismatches.

apple/Tests/CoreRepositoryLifecycleTests.swift

@@ -0,0 +1,131 @@
+import Foundation
+import XCTest
+@preconcurrency import VnidropCore
+@testable import VniDrop
+
+private enum BlockingCoreFactoryError: Error {
+	case stopped
+}
+
+private final class BlockingCoreBindingFactory: CoreBindingFactory, @unchecked Sendable {
+	private let release = DispatchSemaphore(value: 0)
+	private let lock = NSLock()
+	private var initializeCallCount = 0
+	private var initializationStarted = false
+	private var startWaiters: [CheckedContinuation<Void, Never>] = []
+
+	var callCount: Int {
+		lock.lock()
+		defer { lock.unlock() }
+		return initializeCallCount
+	}
+
+	func initialize(
+		appDataDir: String,
+		eventSink: CoreEventSink,
+		networkConfiguration: RelayConfiguration
+	) throws -> VnidropCore {
+		lock.lock()
+		initializeCallCount += 1
+		let call = initializeCallCount
+		initializationStarted = true
+		let waiters = startWaiters
+		startWaiters.removeAll()
+		lock.unlock()
+		waiters.forEach { $0.resume() }
+
+		if call == 1 {
+			release.wait()
+		}
+		throw BlockingCoreFactoryError.stopped
+	}
+
+	func waitUntilInitializationStarts() async {
+		await withCheckedContinuation { continuation in
+			lock.lock()
+			if initializationStarted {
+				lock.unlock()
+				continuation.resume()
+			} else {
+				startWaiters.append(continuation)
+				lock.unlock()
+			}
+		}
+	}
+
+	func unblockInitialization() {
+		release.signal()
+	}
+}
+
+@MainActor
+final class CoreRepositoryLifecycleTests: XCTestCase {
+	func testIdleRequirementRejectsTransfersAndShares() throws {
+		XCTAssertNoThrow(try CoreNetworkLifecycle.requireIdle(activeTransfers: 0, activeShares: 0))
+		XCTAssertThrowsError(
+			try CoreNetworkLifecycle.requireIdle(activeTransfers: 1, activeShares: 0)
+		) { error in
+			XCTAssertEqual(error as? CoreNetworkLifecycleError, .activeNetworkWork)
+		}
+		XCTAssertThrowsError(
+			try CoreNetworkLifecycle.requireIdle(activeTransfers: 0, activeShares: 1)
+		) { error in
+			XCTAssertEqual(error as? CoreNetworkLifecycleError, .activeNetworkWork)
+		}
+	}
+
+	func testRestartSerializesInitializationAndRejectsNewNetworkWork() async {
+		let factory = BlockingCoreBindingFactory()
+		let repository = CoreRepository(coreFactory: factory)
+		let firstInitialization = Task {
+			await repository.initialize(appDataDir: "/tmp/first", networkConfiguration: .automatic)
+		}
+		await factory.waitUntilInitializationStarts()
+
+		let safetyRelease = Task.detached {
+			try? await Task.sleep(nanoseconds: 1_000_000_000)
+			guard !Task.isCancelled else { return }
+			factory.unblockInitialization()
+		}
+		defer {
+			safetyRelease.cancel()
+			factory.unblockInitialization()
+		}
+
+		let concurrentInitialization = await repository.initialize(
+			appDataDir: "/tmp/second",
+			networkConfiguration: RelayConfiguration(mode: .custom, relayURLs: ["https://relay.example"])
+		)
+		assertLifecycleFailure(concurrentInitialization, equals: .transitionInProgress)
+
+		let share = await repository.shareSources(
+			[],
+			transferName: "Blocked",
+			senderName: "Tester",
+			accessPolicy: .requireApproval
+		)
+		assertLifecycleFailure(share, equals: .transitionInProgress)
+
+		let receive = await repository.receive(ticket: "ticket", outputDir: "/tmp", receiverName: "Tester")
+		assertLifecycleFailure(receive, equals: .transitionInProgress)
+		XCTAssertEqual(factory.callCount, 1)
+
+		factory.unblockInitialization()
+		guard case .failure(let error) = await firstInitialization.value else {
+			return XCTFail("The blocking factory should fail the first initialization")
+		}
+		XCTAssertTrue(error is BlockingCoreFactoryError)
+	}
+
+	private func assertLifecycleFailure<T>(
+		_ result: Result<T, Error>,
+		equals expected: CoreNetworkLifecycleError,
+		file: StaticString = #filePath,
+		line: UInt = #line
+	) {
+		guard case .failure(let error) = result else {
+			return XCTFail("Expected lifecycle failure \(expected)", file: file, line: line)
+		}
+		XCTAssertEqual(error as? CoreNetworkLifecycleError, expected, file: file, line: line)
+	}
+}