Use first message timestamp for export filename

Updated chat export logic to use the timestamp of the first message, if available, when generating the export filename and metadata. Falls back to session creation time if no messages are present, ensuring more accurate file naming and metadata.

Author: RAIT-09

src/shared/chat-exporter.ts

@@ -22,7 +22,12 @@ export class ChatExporter {
 		openFile = true,
 	): Promise<string> {
 		const settings = this.plugin.settings.exportSettings;
-		const fileName = this.generateFileName(sessionCreatedAt);
+
+		// Use first message timestamp if available, fallback to session creation time
+		const effectiveTimestamp =
+			messages.length > 0 ? messages[0].timestamp : sessionCreatedAt;
+
+		const fileName = this.generateFileName(effectiveTimestamp);
 		const folderPath = settings.defaultFolder || "Agent Client";
 
 		// Create folder if it doesn't exist
@@ -35,13 +40,13 @@ export class ChatExporter {
 				agentLabel,
 				agentId,
 				sessionId,
-				sessionCreatedAt,
+				effectiveTimestamp,
 			);
 			const chatContent = this.convertMessagesToMarkdown(
 				messages,
 				agentLabel,
 				sessionId,
-				sessionCreatedAt,
+				effectiveTimestamp,
 			);
 			const fullContent = `${frontmatter}\n\n${chatContent}`;