Split exact-domain checker installation tests by semantic owner

[morluto]

Problem

tests/component/checkers/test_exact_domain_checker_installation.py is a shared installation-test hotspot. The conflict pass found the same file in at least 15 of the 17 PRs that were dirty against current main. The file combines checker installation, provider/authority setup, typed handoff behavior, and cross-domain assertions, so unrelated domain additions and checker refactors all edit one central test module.

The result is more than textual churn: a branch can carry a valid domain-specific regression test but still need to resolve against an installation harness whose ownership has moved on current main.

Proposed direction

Split the coverage by semantic owner and lifecycle seam:

• domain/component modules own checker-specific request, replay, and provider behavior;
• a narrow shared contract test owns only generic installation invariants;
• composition tests own complete portfolio wiring, authorization, and publication;
• shared support helpers expose typed, minimal installation profiles instead of forcing every test through one complete exact-domain harness.

Keep real provider and independent-checker authority coverage. Do not replace installation tests with mocks or weaken evidence binding.

Acceptance criteria

• A new domain checker can add focused installation coverage without editing one portfolio-wide test file.
• Generic installation invariants remain covered once at the narrowest appropriate seam.
• Provider-unavailable, unauthorized, typed-value/reference, and publication cases retain explicit ownership.
• Test fixtures make the required runtime/profile visible and do not reinstall the complete checker portfolio for narrow component behavior.
• An architecture/test-ownership check prevents new domain-specific assertions from returning to the shared monolith.

This issue is intentionally narrower than #1405, which tracks deleting the legacy exact-domain semantic maps, and #1385, which tracks repeated complete checker installation in E2E journeys.

[morluto]

The current reconciliation of #1301 (#1301) hit tests/component/checkers/test_exact_domain_checker_installation.py in the same conflict set as the production installer. The conflict was not feature behavior; it was a shared installation-test fixture expectation (optional=False) changing alongside runtime semantics.

This is evidence that the installation suite is still a broad semantic-owner hub. Splitting required/optional provider installation, declaration runtime grouping, and domain-specific checker cases into owner-aligned suites would reduce conflict pressure and make future feature merges less dependent on unrelated test edits.

[morluto]

Closing as superseded by the stateless redesign. tests/component/checkers/test_exact_domain_checker_installation.py, exact_domain_checkers.py, checker installation tests, and the entire checker installation infrastructure have been deleted. The conflict-prone shared test file no longer exists.