fix(settings): align preferences with runtime behavior

Sources/Firelink/Settings/LocationsSettingsPane.swift

@@ -28,29 +28,46 @@ struct DirectoryPickerRow: View {
     let category: DownloadCategory
 
     @State private var path = ""
+    @State private var message = ""
 
     var body: some View {
         LabeledContent {
-            HStack(spacing: 8) {
-                TextField("Folder path", text: Binding(
-                    get: { settings.downloadDirectories[category] ?? path },
-                    set: { newValue in
-                        path = newValue
-                        settings.setDirectory(newValue, for: category)
-                    }
-                ))
-                .textFieldStyle(.roundedBorder)
-                .font(.system(.body, design: .monospaced))
+            VStack(alignment: .leading, spacing: 4) {
+                HStack(spacing: 8) {
+                    TextField("Folder path", text: $path)
+                        .textFieldStyle(.roundedBorder)
+                        .font(.system(.body, design: .monospaced))
+                        .onSubmit {
+                            applyPath()
+                        }
 
-                Button {
-                    selectFolder()
-                } label: {
-                    Label("Select", systemImage: "folder.badge.plus")
+                    Button {
+                        applyPath()
+                    } label: {
+                        Label("Apply", systemImage: "checkmark")
+                    }
+                    .disabled(path.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
+
+                    Button {
+                        selectFolder()
+                    } label: {
+                        Label("Select", systemImage: "folder.badge.plus")
+                    }
                 }
+
+                Text(message.isEmpty ? statusMessage(for: path) : message)
+                    .font(.caption)
+                    .foregroundStyle(message.isEmpty ? .secondary : .primary)
             }
         } label: {
             Label(category.rawValue, systemImage: category.symbolName)
         }
+        .onAppear {
+            syncPathFromSettings()
+        }
+        .onChange(of: settings.downloadDirectories[category]) { _, _ in
+            syncPathFromSettings()
+        }
     }
 
     private func selectFolder() {
@@ -62,7 +79,70 @@ struct DirectoryPickerRow: View {
         panel.directoryURL = settings.destinationDirectory(for: category)
 
         if panel.runModal() == .OK, let url = panel.url {
+            path = url.path
             settings.setDirectory(url.path, for: category)
+            message = "Saved."
         }
     }
+
+    private func syncPathFromSettings() {
+        path = settings.downloadDirectories[category] ?? settings.destinationDirectory(for: category).path
+        message = ""
+    }
+
+    private func applyPath() {
+        let trimmed = path.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty else {
+            message = "Enter a folder path."
+            return
+        }
+
+        let expanded = NSString(string: trimmed).expandingTildeInPath
+        var isDirectory: ObjCBool = false
+
+        if FileManager.default.fileExists(atPath: expanded, isDirectory: &isDirectory) {
+            guard isDirectory.boolValue else {
+                message = "This path points to a file, not a folder."
+                return
+            }
+        } else {
+            do {
+                try FileManager.default.createDirectory(
+                    at: URL(fileURLWithPath: expanded, isDirectory: true),
+                    withIntermediateDirectories: true
+                )
+            } catch {
+                message = "Could not create folder: \(error.localizedDescription)"
+                return
+            }
+        }
+
+        guard FileManager.default.isWritableFile(atPath: expanded) else {
+            message = "Firelink cannot write to this folder."
+            return
+        }
+
+        settings.setDirectory(expanded, for: category)
+        path = expanded
+        message = "Saved."
+    }
+
+    private func statusMessage(for path: String) -> String {
+        let trimmed = path.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty else { return "Enter a folder path." }
+
+        let expanded = NSString(string: trimmed).expandingTildeInPath
+        var isDirectory: ObjCBool = false
+
+        if FileManager.default.fileExists(atPath: expanded, isDirectory: &isDirectory) {
+            if !isDirectory.boolValue {
+                return "This path points to a file, not a folder."
+            }
+            return FileManager.default.isWritableFile(atPath: expanded)
+                ? "Ready."
+                : "Firelink cannot write to this folder."
+        }
+
+        return "Folder will be created when applied."
+    }
 }