Tasks: Consolidation / done-bookkeeping regressions (#6071, #6073)

Bugfix mission, single_branch topology, direct_repo execution on issue-6071-consolidation-bookkeeping-regressions. Each WP is one independently-reviewable slice mapping to named tests; red-first reproductions are recorded in research/.

WPSliceClusterFixes (named tests)Surface
WP01Diagnosis + scaffolding—records red-first reproductions; no product/test changeresearch/, mission docs
WP02Post-merge done-check via canonical reducerA (FR-001/002)test_merge_coord_topology_1772::test_post_merge_validation_reads_in_branch_status_pathconsolidation/done_bookkeeping.py, tests/consolidation/test_done_bookkeeping_seam.py
WP03Bare-slug composed-dir teardown on resumeB (FR-003)test_bare_slug_coord_mission_consolidates_again_after_the_bookkeeping_commit_failedconsolidation/phase_teardown.py
WP04Skip-lanes fixture realism (test-data re-pin)C (FR-004)test_issue_2745_merge_skip_lanes ×3tests/specify_cli/cli/commands/test_issue_2745_merge_skip_lanes.py
WP05Interrupted-fold dirty detectionD (FR-005)test_a_run_killed_inside_the_fold_... ×2pre-mutation preflight (entry_preflight/resume_recovery/preflight)

Dependencies: WP02–WP05 are independent of each other; all depend on WP01 (diagnosis-first). Validation surface per WP is its named test plus the owning directory; see plan.md §Testing.