[Bug] ACP/acpx session accepted but never closes the loop; no history, no announce, no stream log

Summary

Using runtime: "acp" with opencode, the spawned ACP session is accepted but does not close the loop.

Observed behavior:

• sessions_spawn returns status: "accepted"
• child sessionKey is created
• session_status remains running
• no completion callback / no visible parent summary
• sessions_history for the child session is empty ([])
• no .acp-stream.jsonl / no streamLogPath evidence found

I ran an A/B test with a single variable:

• A: default/local plugin command source
• B: explicit fixed command source:
  /opt/homebrew/lib/node_modules/openclaw/extensions/acpx/node_modules/.bin/acpx

Result:

• A and B behaved the same
• therefore this does not appear to be caused by command source differences
• likely root cause is upstream ACP/acpx completion + transcript/history persistence + announce delivery

Environment

• OpenClaw: 2026.3.2
• Runtime: ACP
• Backend: acpx
• Agent: opencode
• OS: macOS (Darwin arm64)
• Channel under test: Feishu DM (no thread binding)

Minimal repro

Spawn the shortest possible ACP task:

Task A:
Reply exactly: ABTEST_A_OK

Task B:
Reply exactly: ABTEST_B_OK

For both:

1. spawn ACP session
2. observe accepted
3. inspect child sessionKey
4. poll session_status
5. inspect sessions_history
6. inspect stream log path / .acp-stream.jsonl

Expected

• ACP session reaches completed state
• completion is surfaced back to parent
• child session history contains assistant output
• stream log exists when applicable
• no orphaned running session remains

Actual

• session stays running
• no completion/announce visible
• child history is empty
• no stream log evidence
• repeated across A/B with different command source

Notes

This seems consistent with recently reported ACP issues around:

• no completion callback / silent stalls
• ACP run sessions not persisting output to history
• missing transcript / no .jsonl for ACP sessions
• suppressed completion announcements