perf: ensure stable session ordering with secondary sort and reliable timestamp fallbacks

Author: N1kky-wed

packages/cli/src/ui/components/SessionBrowser/utils.ts

@@ -24,10 +24,15 @@ export const sortSessions = (
 ): SessionInfo[] => {
   const sorted = [...sessions].sort((a, b) => {
     switch (sortBy) {
-      case 'date':
+      case 'date': {
+        const diff =
+          new Date(b.lastUpdated).getTime() - new Date(a.lastUpdated).getTime();
+        if (diff !== 0) return diff;
+        // Stable secondary sort by startTime
         return (
-          new Date(b.lastUpdated).getTime() - new Date(a.lastUpdated).getTime()
+          new Date(b.startTime).getTime() - new Date(a.startTime).getTime()
         );
+      }
       case 'messages':
         return b.messageCount - a.messageCount;
       case 'name':

packages/core/src/services/chatRecordingService.ts

@@ -162,10 +162,32 @@ export async function loadConversationRecord(
 
         const sessionId = getMatch(headStr, /"sessionId"\s*:\s*"([^"]+)"/);
         const projectHash = getMatch(headStr, /"projectHash"\s*:\s*"([^"]+)"/);
-        const startTime = getMatch(headStr, /"startTime"\s*:\s*"([^"]+)"/);
+        let startTime = getMatch(headStr, /"startTime"\s*:\s*"([^"]+)"/);
+        let filenameTimestamp: string | undefined;
+
+        // Fallback: Extract startTime from filename if not in header (format: session-YYYY-MM-DDTHH-MM-8CHARS.jsonl)
+        if (!startTime || !getMatch(tailStr, /"lastUpdated"\s*:\s*"([^"]+)"/)) {
+          const basename = path.basename(filePath);
+          const timeMatch = basename.match(
+            /session-(\d{4}-\d{2}-\d{2}T\d{2}-\d{2})/,
+          );
+          if (timeMatch) {
+            // Convert session-2026-05-10T11-45-... to valid ISO 2026-05-10T11:45:00Z
+            filenameTimestamp =
+              timeMatch[1].replace(/-/g, (m, offset) =>
+                offset > 10 ? ':' : '-',
+              ) + ':00Z';
+          }
+        }
+
+        if (!startTime) {
+          startTime = filenameTimestamp;
+        }
+
         const lastUpdated =
           getMatch(tailStr, /"lastUpdated"\s*:\s*"([^"]+)"/) ||
-          getMatch(headStr, /"lastUpdated"\s*:\s*"([^"]+)"/);
+          getMatch(headStr, /"lastUpdated"\s*:\s*"([^"]+)"/) ||
+          filenameTimestamp;
         const summary =
           getMatch(tailStr, /"summary"\s*:\s*"((?:[^"\\\\]|\\\\.)*)"/) ||
           getMatch(headStr, /"summary"\s*:\s*"((?:[^"\\\\]|\\\\.)*)"/);