Add taskbar controls and summary oneliner

MeetingAssistant/Summary/MeetingSummaryTools.cs

@@ -206,8 +206,19 @@ public sealed class MeetingSummaryTools
         return $"Deleted identity {deletion.Identity} and relabeled transcript speaker mentions to {deletion.Replacement}.";
     }
 
-    public async Task<string> WriteSummary(string markdown, string? title = null)
+    public async Task<string> WriteSummary(string markdown, string oneliner, string? title = null)
     {
+        if (string.IsNullOrWhiteSpace(oneliner))
+        {
+            return "Refused: oneliner must not be empty.";
+        }
+
+        var trimmedOneLiner = oneliner.Trim();
+        if (ContainsLineBreak(trimmedOneLiner))
+        {
+            return "Refused: oneliner must be a single line.";
+        }
+
         Directory.CreateDirectory(Path.GetDirectoryName(artifacts.SummaryPath)!);
         var meetingNote = await ReadMeetingNoteAsync();
         var summaryTitle = string.IsNullOrWhiteSpace(meetingNote.Frontmatter.Title)
@@ -218,6 +229,7 @@ public sealed class MeetingSummaryTools
             meetingNote,
             string.IsNullOrWhiteSpace(summaryTitle) ? "Meeting Summary" : summaryTitle,
             CancellationToken.None);
+        frontmatter.OneLiner = trimmedOneLiner;
         await File.WriteAllTextAsync(
             artifacts.SummaryPath,
             MeetingArtifactFrontmatterRenderer.Render(frontmatter, markdown));
@@ -225,6 +237,12 @@ public sealed class MeetingSummaryTools
         return artifacts.SummaryPath;
     }
 
+    private static bool ContainsLineBreak(string value)
+    {
+        return value.Contains('\n', StringComparison.Ordinal) ||
+            value.Contains('\r', StringComparison.Ordinal);
+    }
+
     public bool SummaryWasWritten { get; private set; }
 
     public async Task<string> WriteContext(