Remove speaker prefix from rendered transcript lines.

Render timeline output as timestamp + text only so transcripts no longer prepend labels like \"You:\".

Co-authored-by: Cursor <cursoragent@cursor.com>

meetings_app/Transcription/MeetingTranscriptionService.swift

@@ -386,7 +386,7 @@ final class MeetingTranscriptionService {
 
 extension Array where Element == TranscriptSegment {
     /// Renders segments as a human-readable timeline like:
-    /// `[00:12] You: Hello everyone.`
+    /// `[00:12] Hello everyone.`
     func renderedTimelineText() -> String {
         let formatter: (TimeInterval) -> String = { seconds in
             let total = Int(seconds.rounded(.down))
@@ -399,7 +399,7 @@ extension Array where Element == TranscriptSegment {
             return String(format: "%02d:%02d", m, s)
         }
         return self.map { segment in
-            "[\(formatter(segment.startOffset))] \(segment.speaker): \(segment.text)"
+            "[\(formatter(segment.startOffset))] \(segment.text)"
         }.joined(separator: "\n")
     }
 }