test(mission-control): add AC0 auth readiness probe + auth gate artifacts

[krusty-agent]

Summary

• add AC0 auth readiness probe so Mission Control suite always executes one deterministic acceptance check in CI
• keep existing AC1-AC5 skip behavior for OTP-gated environments
• auto-attach auth diagnostics artifacts when auth shell is unavailable (json + screenshot + html)
• document new artifact behavior in e2e README

Why

CI runs without manual OTP were skipping AC paths with limited context. This adds a runnable probe and captures enough artifacts to unblock triage when auth env vars are missing/misaligned.

Validation

lisa-temp@0.0.0 test:e2e
playwright test e2e/mission-control-phase1.spec.ts -g AC0 auth readiness probe (pass)

lisa-temp@0.0.0 test:e2e
playwright test e2e/mission-control-phase1.spec.ts -g baseline harness boots app shell|AC4 no-regression core UX (1 pass, 1 skipped due auth gate)

[krusty-agent]

Superseded by consolidated PR #167: #167