Description:
When creating a new session via /new or /reset command, previous sessions are saved to disk as .reset.* files but are not listed in the session selector UI.

Steps to Reproduce:

1. Use /new or /reset to create a new session
2. Observe that only the current session appears in the session list
3. Previous sessions are saved as .reset.* files but not indexed

Expected Behavior:
Previous sessions should be visible in the session list so users can switch back to them.

Technical Details:

• Sessions are saved to: ~/.openclaw/agents/main/sessions/
• Files exist: 2 previous .reset.* session files present
• sessions.json only tracks the current active session
• UI shows only "Main Session"

Environment:

• macOS
• OpenClaw version: 2026.3.8
• Channel: webchat