chore(enterprise): bump submodule to enterprise-main tip e898cef — ent#220 rooms security fix

[vybe]

What

Re-points src/backend/enterprise 6f073c73 → e898cef8 (enterprise-main TIP).

Why

The 0.8.5 freeze-plan recheck (2026-07-26) found the pin stale by one commit — and that commit is the ent#220 rooms security fix (moderator-only lifecycle mutations + participant-cap re-check on add). Without this bump, v0.8.5 ships the Sessions/rooms feature without its role-enforcement half. This is the third occurrence of the stale-pointer class (ent#185); the freeze plan's own pre-cut checklist requires the pointer at enterprise-main TIP at cut time.

Notes

• Verified 6f073c73 is an ancestor of e898cef8; the delta is exactly one commit (enterprise PR fix: Slack message router ignores per-agent execution timeout (TIMEOUT-001) #221).
• The recheck also found a latent defect in enterprise backend/__init__.py (duplicate skill_runner registration + three modules bypassing the ent#196 _register_module isolation wrapper) — present at BOTH the old pin and this tip, so this bump neither introduces nor fixes it; it is filed separately for next cycle.

🤖 Generated with Claude Code

[AndriiPasternak31]

/validate-pr — APPROVE.

Verified against the enterprise repo, not just the PR body:

• compare 6f073c73...e898cef8 → status: ahead, ahead_by: 1, behind_by: 0 — the ancestor + exactly-one-commit claim is exact.
• That commit is e898cef8 fix(rooms): moderator-only lifecycle mutations + re-check participant cap on add (ent#220) (#221) — the security fix named in the body.

Check	Status
Base branch	✅ dev
PR size	✅ 1 file, +1/-1
Commit message	✅ conventional, descriptive
Security scan	✅ clean (secrets/emails/IPs/creds all 0)
Build + config packaging	➖ no backend module / no os.getenv
Docs required	➖ chore, submodule pointer only
CI	✅ all green

Notes (non-blocking):

• No closing keyword — correct here: this bump does not fix ent#220 (enterprise PR #221 did), and ent#220 remains open for its documented residuals, consistent with the Known-limitations block in #1778.
• Redundant with #1777, which resolves the same gitlink to the same SHA. Merging in either order is clean — verified by simulation.