feat: Add FFmpeg audio recording and ydotool typing backends, making them configurable.

Configuration/ToakConfig.cs

@@ -4,6 +4,7 @@ public class ToakConfig
 {
     public string GroqApiKey { get; set; } = string.Empty;
     public string TypingBackend { get; set; } = "xdotool"; // wtype or xdotool
+    public string AudioBackend { get; set; } = "pw-record"; // pw-record or ffmpeg
     public bool ModulePunctuation { get; set; } = true;
     public bool ModuleTechnicalSanitization { get; set; } = true;