test(e2e): pin munger packets window (port of upstream #1942)

[adminopenclaw8-sketch]

Summary

• pin the packet-page window to 24 hours in the munger slide-over E2E
• keep the test focused on slide-over behavior instead of fixture age
• preserve the existing three regression scenarios unchanged

Upstream

Fork port of Kpa-clawbot/CoreScope#1942, applied to fork master 1d2e0fee7cc9528d6bd83ae2c95d04272d0b0335.

Verification

• node --check test-slideover-1168-munger-e2e.js
• local Go server with a freshened and migrated E2E fixture
• BASE_URL=http://localhost:13592 node test-slideover-1168-munger-e2e.js — 3 passed, 0 failed
• git diff --check

Scope

Test-only change. No production behavior, workflow, deployment, staging, or configuration changes.