Skip media-wipe detached tasks under tests (shared-filesystem race)

panicClearAllData and clearCurrentPublicTimeline delete the real
~/Library/Application Support/files tree in detached utility-priority
tasks. The SPM test process shares that tree and ChatViewModelTests
invoke both methods, so under parallel scheduling the wipe lands at a
nondeterministic time — deleting media a concurrently running test just
wrote (and the developer's real app data with it). Guard both with the
existing TestEnvironment.isRunningTests pattern, mirroring the same fix
on feat/mesh-diagnostics (#1377).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

bitchat/ViewModels/ChatPublicConversationCoordinator.swift

@@ -291,6 +291,11 @@ final class ChatPublicConversationCoordinator: PublicMessagePipelineDelegate {
         context.clearPublicConversation(ConversationID(channelID: context.activeChannel))
 
         Task.detached(priority: .utility) {
+            // Skipped under tests: the test process shares the user's real
+            // ~/Library/Application Support/files tree, and this detached
+            // wipe fires at a nondeterministic time — racing tests that
+            // write media there (see the same guard in panicClearAllData).
+            guard !TestEnvironment.isRunningTests else { return }
             do {
                 let base = try FileManager.default.url(
                     for: .applicationSupportDirectory,

bitchat/ViewModels/ChatViewModel.swift

@@ -1274,6 +1274,13 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
 
         // Delete ALL media files (incoming and outgoing) in background
         Task.detached(priority: .utility) {
+            // Skipped under tests: the test process shares the user's real
+            // ~/Library/Application Support/files tree, and this detached
+            // utility-priority wipe fires at a nondeterministic time —
+            // deleting media that concurrently running tests (e.g. the
+            // sendImage flow) just wrote there, and the developer's real
+            // app data with it.
+            guard !TestEnvironment.isRunningTests else { return }
             do {
                 let base = try FileManager.default.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
                 let filesDir = base.appendingPathComponent("files", isDirectory: true)