test: migrate repo-shaped suites onto the canonical repo fixture builder #316
Description
Follow-up from issue #311.
Summary
Now that the shared repo fixture builder, base repos, and scenario overlays exist, migrate additional repository-shaped suites away from repeated mkdtemp + git init + config boilerplate and onto the canonical fixture substrate.
Why
Issue #311 should stay focused on establishing the substrate itself. Broader suite migration is valuable, but it is separate follow-on work. Keeping it separate prevents scope creep while still preserving the adoption plan.
Candidate suites
- contracts.integration
- epoch
- diff
- content
- merge
- import
- review
- views
Acceptance criteria
- at least the highest-value repo-shaped suites are migrated to the shared fixture helper
- duplicated temp-repo setup boilerplate is materially reduced
- migrated suites still preserve the history/topology semantics they care about
- new Hill 1 work prefers the shared fixture substrate by default
Related
- issue test: build canonical repo fixture builder with base repos and overlays #311
- ADR-0006
- docs/design/repo-fixture-strategy.md