Added transcription of audio and video files to local data sources (#1081)

Co-authored-by: Paul Koudelka <106623909+PaulKoudelka@users.noreply.github.com>

app/MindWork AI Studio/Tools/Media/PersistentMediaTranscriptResult.cs

@@ -0,0 +1,26 @@
+using AIStudio.Tools.Rust;
+
+namespace AIStudio.Tools.Media;
+
+/// <summary>
+/// The outcome of a request for a persistent transcript, cf. PersistentMediaTranscript.
+/// </summary>
+/// <remarks>
+/// The transcript itself is not part of it: whoever needs the text reads the file at
+/// TranscriptPath, so a transcript reaches the AI by the same path no matter whether it was just
+/// made or stored long ago.
+/// </remarks>
+/// <param name="Status">How the request ended.</param>
+/// <param name="TranscriptPath">The path of the transcript; empty when the place could not be determined.</param>
+/// <param name="Key">What identifies the transcript at its location; empty when the place could not be determined.</param>
+/// <param name="Reused">Whether an existing transcript was used instead of a new transcription.</param>
+/// <param name="UserMessage">A localized explanation for every status but READY and CANCELLED.</param>
+/// <param name="ErrorCode">Why the media pipeline failed, for TRANSCRIPTION_FAILED, when it is known.</param>
+internal sealed record PersistentMediaTranscriptResult(PersistentMediaTranscriptStatus Status, string TranscriptPath, string Key, bool Reused, string UserMessage, MediaJobErrorCode? ErrorCode = null)
+{
+    public static PersistentMediaTranscriptResult Ready(MediaTranscriptSlot slot, bool reused) => new(PersistentMediaTranscriptStatus.READY, slot.Path, slot.Key, reused, string.Empty);
+
+    public static PersistentMediaTranscriptResult Cancelled() => new(PersistentMediaTranscriptStatus.CANCELLED, string.Empty, string.Empty, false, string.Empty);
+
+    public static PersistentMediaTranscriptResult Unavailable(PersistentMediaTranscriptStatus status, MediaTranscriptSlot? slot, string userMessage, MediaJobErrorCode? errorCode = null) => new(status, slot?.Path ?? string.Empty, slot?.Key ?? string.Empty, false, userMessage, errorCode);
+}