fix: resolve critical download bugs and configuration issues

- proxy: Prevent SOCKS5 proxy type from being silently converted to HTTP.
- core: Remove DispatchGroup from MediaDownloadEngine to fix a hang caused by unclosed output pipes when child processes inherit file descriptors.
- settings: Fix keychain primer logic to prevent wiping extension credentials on debug builds.
- ui: Resolve a batch rename collision in AddDownloadsView by properly checking new filenames against the current batch sequence.

Sources/Firelink/AddDownloadsView.swift

@@ -701,7 +701,7 @@ struct AddDownloadsView: View {
                     var count = 1
                     let base = URL(fileURLWithPath: newName).deletingPathExtension().lastPathComponent
                     let ext = URL(fileURLWithPath: newName).pathExtension
-                    while controller.downloads.contains(where: { $0.destinationDirectory == destURL && $0.fileName == newName }) || FileManager.default.fileExists(atPath: destURL.appendingPathComponent(newName).path) {
+                    while controller.downloads.contains(where: { $0.destinationDirectory == destURL && $0.fileName == newName }) || FileManager.default.fileExists(atPath: destURL.appendingPathComponent(newName).path) || finalDownloads.prefix(upTo: index).contains(where: { (overrideDirectory ?? $0.defaultDirectory) == destURL && $0.fileName == newName }) {
                         newName = "\(base) (\(count))" + (ext.isEmpty ? "" : ".\(ext)")
                         count += 1
                     }

Sources/Firelink/AppSettings.swift

@@ -93,9 +93,6 @@ struct ProxySettings: Codable, Equatable, Sendable {
         var copy = self
         copy.host = copy.host.trimmingCharacters(in: .whitespacesAndNewlines)
         copy.port = min(max(copy.port, 1), 65_535)
-        if copy.type != .http {
-            copy.type = .http
-        }
         return copy
     }
 
@@ -301,16 +298,13 @@ final class AppSettings: ObservableObject {
         }
 
         if granted {
+            if let token = KeychainCredentialStore.extensionToken() {
+                extensionPairingToken = token
+            } else {
+                extensionPairingToken = Self.generateSecureToken()
+            }
             if needsPrimer {
                 showKeychainPrimer = true
-                extensionPairingToken = ""
-            } else {
-                if let token = KeychainCredentialStore.extensionToken() {
-                    extensionPairingToken = token
-                } else {
-                    extensionPairingToken = Self.generateSecureToken()
-                    // The didSet of extensionPairingToken will handle setting it in the keychain since isKeychainAccessGranted is true.
-                }
             }
         } else {
             extensionPairingToken = ""

Sources/Firelink/MediaDownloadEngine.swift

@@ -100,16 +100,10 @@ final class MediaDownloadEngine: @unchecked Sendable {
             messageUpdate: messageUpdate
         )
 
-        let group = DispatchGroup()
-        group.enter() // output
-        group.enter() // error
-        group.enter() // process
-
         outputPipe.fileHandleForReading.readabilityHandler = { handle in
             let data = handle.availableData
             if data.isEmpty {
                 handle.readabilityHandler = nil
-                group.leave()
             } else if let text = String(data: data, encoding: .utf8) {
                 outputHandler.handle(text)
             }
@@ -119,7 +113,6 @@ final class MediaDownloadEngine: @unchecked Sendable {
             let data = handle.availableData
             if data.isEmpty {
                 handle.readabilityHandler = nil
-                group.leave()
             } else {
                 errorBuffer.append(data)
                 if let text = String(data: data, encoding: .utf8) {
@@ -128,16 +121,15 @@ final class MediaDownloadEngine: @unchecked Sendable {
             }
         }
 
-        process.terminationHandler = { _ in
+        process.terminationHandler = { finishedProcess in
-            group.leave()
+            outputPipe.fileHandleForReading.readabilityHandler = nil
-        }
+            errorPipe.fileHandleForReading.readabilityHandler = nil
             
-        group.notify(queue: .global()) {
+            if finishedProcess.terminationStatus == 0 {
-            if process.terminationStatus == 0 {
                 completionGate.complete(.success(Self.resolvedOutputURL(for: item, tracker: outputPathTracker)))
             } else {
                 let errorString = String(data: errorBuffer.data, encoding: .utf8)?.trimmingCharacters(in: .whitespacesAndNewlines) ?? "Unknown Error"
-                completionGate.complete(.failure(EngineError.launchFailed(Self.cleanErrorMessage(errorString, status: process.terminationStatus))))
+                completionGate.complete(.failure(EngineError.launchFailed(Self.cleanErrorMessage(errorString, status: finishedProcess.terminationStatus))))
             }
         }