fix: session-memory hook finds previous session file after /new/reset

When /new or /reset is triggered, the session file gets rotated
before the hook runs. The hook was reading the new (empty) file
instead of the previous session content.

This fix:
1. Checks if the session file looks like a reset file (.reset.)
2. Falls back to finding the most recent non-reset .jsonl file
3. Logs debug info about which file was used

Fixes openclaw/openclaw#18088

src/hooks/bundled/session-memory/handler.ts

@@ -133,12 +133,35 @@ const saveSessionToMemory: HookHandler = async (event) => {
     const dateStr = now.toISOString().split("T")[0]; // YYYY-MM-DD
 
     // Generate descriptive slug from session using LLM
+    // Prefer previousSessionEntry (old session before /new) over current (which may be empty)
     const sessionEntry = (context.previousSessionEntry || context.sessionEntry || {}) as Record<
       string,
       unknown
     >;
+    let currentSessionFile = (sessionEntry.sessionFile as string) || undefined;
+
+    // If sessionFile is empty or looks like a new/reset file, try to find the previous session file
+    if (!currentSessionFile || currentSessionFile.includes(".reset.")) {
+      // Look for previous session file in the sessions directory
+      const sessionsDir = path.dirname(currentSessionFile || "");
+      if (sessionsDir) {
+        try {
+          const files = await fs.readdir(sessionsDir);
+          const sessionFiles = files
+            .filter((f) => f.endsWith(".jsonl") && !f.includes(".reset."))
+            .toSorted()
+            .toReversed();
+          if (sessionFiles.length > 0) {
+            currentSessionFile = path.join(sessionsDir, sessionFiles[0]);
+            log.debug("Found previous session file", { file: currentSessionFile });
+          }
+        } catch {
+          // Ignore errors reading directory
+        }
+      }
+    }
+
     const currentSessionId = sessionEntry.sessionId as string;
-    const currentSessionFile = sessionEntry.sessionFile as string;
 
     log.debug("Session context resolved", {
       sessionId: currentSessionId,