[QA] Add cross-agent conformance and E2E matrix

[teseo]

Kind

acceptance-gate

Goal

Prove that every support claim in the matrix is backed by repeatable conformance and lifecycle tests.

Non-goals

• Re-testing undocumented agent behavior without a fixture.
• Replacing host-specific smoke tests.
• Treating advisory behavior as enforcement.

Invariants

• Every adapter runs the same canonical decision scenarios.
• Tests distinguish allow, deny, advisory, timeout, stale state, and session end.
• Fail-open and fail-closed semantics are asserted explicitly.
• Test artifacts identify agent, version, surface, and result.

Behavioral contract / States

A conformance runner provisions an isolated home, installs one adapter, executes the shared scenario set, and emits machine-readable results plus a human summary.

Scope surface

tests/conformance, tests/test.sh, adapter fixtures, CI configuration, and result documentation.

Acceptance

• Add scenarios for outside-hours, blocked period, wind-down, max session, stale state, concurrent sessions, and uninstall.
• Run: bash tests/test.sh, bash tests/test_install.sh, python3 -m pytest tests/test_guard.py -v, and node --test tests/test_guard.mjs.
• CI fails when a claimed full-support adapter lacks a passing conformance result.
• Publish one result artifact per supported agent/surface.

Split triggers

• A host cannot execute the shared fixture model.
• A desktop-only scenario requires a separate manual acceptance gate.

Dependencies / Parent

Blocked by: #4, #5, #6, #7, #8, #9, #10, #11
Parent Epic: #15