[bug] WebUI/OpenClaw sessions can never be wrapped — triggerWrap requires tmuxSession but webui records null

[Jason-Vaughan]

What

WebUI-launched sessions (including OpenClaw webui sessions) can never be wrapped. The session-wrap trigger is gated on a tmux session handle that webui sessions never have.

Why / root cause

Verified during the 4.0 methodology re-arch design (6-agent code read, 2026-06-12):

• lib/sessions.js:363 — webui-mode sessions are recorded with tmuxSession: null.
• lib/sessions.js:987 — triggerWrap requires a non-null tmuxSession before it will run.

So any session created via the webui transport falls through the wrap gate silently: no L2 wrap pipeline, no hooks, no Critic — even though the V2 wrap pipeline is server-side and does not actually need a tmux pane.

Expected behavior

WebUI sessions should reach triggerWrap and run the server-side (non-tmux) V2 wrap path. The tmux requirement should be relaxed/branched so a tmuxSession: null webui session routes to the server-side wrap instead of being skipped.

Repro

1. Launch an OpenClaw session in webui mode (not ssh/tmux).
2. Attempt a session wrap.
3. Observe the wrap never triggers (the tmuxSession guard at sessions.js:987 short-circuits).

Notes

• Folded into the 4.0 build plan as chunk 0 (smallest first step). Fix lives in lib/sessions.js; regression test belongs in test/sessions-webui.test.js / test/session-wrapper.test.js.
• Verify the server-side V2 wrap path itself doesn't assume a tmux pane capture before relying on it.