Prompt history: list preview shows the message as written, not the engine's time line (#660)

Version 0.1.13.

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

src/ClawdDotNet.Core/Transcripts/RunTranscriptRecorder.cs

@@ -34,6 +34,9 @@ public sealed class RunTranscriptRecorder
 
     public bool Enabled { get; }
     public string? SystemPrompt { get; private set; }
+
+    /// <summary>The message as sent by its author - without the time line the engine prepends.</summary>
+    public string? PromptPreview { get; private set; }
     public DateTime StartedAt { get; }
 
     public RunTranscriptRecorder(bool enabled = true, TimeProvider? clock = null)
@@ -45,11 +48,14 @@ public sealed class RunTranscriptRecorder
 
     // ─── Engine hooks ───
 
-    public void Begin(string? systemPrompt, string userMessage)
+    /// <param name="sentMessage">What the model received, including what the engine added.</param>
+    /// <param name="originalMessage">The message as its author wrote it - the list preview.</param>
+    public void Begin(string? systemPrompt, string sentMessage, string? originalMessage = null)
     {
         if (!Enabled) return;
         SystemPrompt = string.IsNullOrWhiteSpace(systemPrompt) ? null : SecretScrubber.Scrub(systemPrompt);
-        Add(TranscriptEntryKind.User, userMessage, MaxTextChars);
+        PromptPreview = SecretScrubber.Scrub(originalMessage ?? sentMessage);
+        Add(TranscriptEntryKind.User, sentMessage, MaxTextChars);
     }
 
     /// <summary>A message the engine sent on its own (follow-up after an empty answer etc.).</summary>
@@ -127,6 +133,7 @@ public sealed class RunTranscriptRecorder
                 CompletedAt = _clock.GetUtcNow().UtcDateTime,
                 Status = status,
                 SystemPromptHash = SystemPrompt is null ? null : Hash(SystemPrompt),
+                PromptPreview = PromptPreview,
                 Entries = _entries.ToList(),
                 SizeChars = _size,
                 Truncated = _truncated