Bug Description

The OpenClaw Control UI dashboard dropdown displays all session records including completed, killed, and timed-out subagent sessions. These persist indefinitely even after the subagents are no longer running.

Current Behavior

• sessions_list API returns all sessions from the transcript store
• Dashboard dropdown shows 9+ sessions (1 main + 8 historical subagents)
• Completed/killed subagents remain visible:
  • smoke-test (completed)
  • dns-config (timeout)
  • vercel-deploy (timeout)
  • email-system (completed)
  • design-system (completed)
  • stripe-checkout (completed)
  • rebuild-pages (completed)
  • onboarding-flow (completed)

Expected Behavior

Dashboard dropdown should show:

1. Active sessions only (running subagents + main session), OR
2. Recent sessions (e.g., last 24-48 hours) with pagination, OR
3. Provide a cleanup/archive UI to remove historical session records

Impact

• Visual clutter in the dashboard
• Confusing UX (appears like 10 agents are running when only 1 is active)
• No way to clean up via UI or CLI
• Session transcript files accumulate at ~/.openclaw/agents/main/sessions/*.jsonl

Steps to Reproduce

1. Spawn multiple subagents via sessions_spawn
2. Let them complete or kill them via subagents kill
3. Open Control UI dashboard
4. Check session dropdown — all historical sessions still appear

Environment

• OpenClaw version: latest (dev channel)
• OS: Pop!_OS 24.04 LTS (Linux 6.18.7)
• Node: v25.6.1
• Channel: Telegram
• Model: bailian/qwen3.5-plus

Proposed Solutions

Option A: Filter by Status (Recommended)

• Dashboard dropdown shows only active sessions
• Add "Show History" toggle to view completed sessions
• API: sessions_list?activeOnly=true

Option B: Time-Based Retention

• Default: show sessions from last 24 hours
• Pagination for older sessions
• Config: dashboard.sessionRetentionHours

Option C: Manual Cleanup

• Add openclaw sessions cleanup CLI command
• Add "Clear History" button in dashboard
• Archive transcripts to ~/.openclaw/agents/main/sessions/archive/

Additional Context

Session files are stored at:

~/.openclaw/agents/main/sessions/<sessionId>.jsonl

Current workaround: manually delete .jsonl files (not recommended without proper cleanup).

Priority: Medium (UX issue, not functional blocker)
Labels: bug, ui, sessions