Walking skeleton: end-to-end coordinate-heal thread

Part of plans/ledger-coordinate-migration — the generic, plan-agnostic on-serve coordinate heal.

Items

• w-d1300938 — Author a fixture plan under scripts/heal_ledger_coordinates_runtime/tests/fixtures/ that declares matrix opt-in taxonomies (mechanism_class_taxonomy + domain_taxonomy) and a ledger carrying >=2 coordinate-less cycle entries (empty coordinate_map sidecar).
• w-a52e16fd — Thread the whole pipeline once with stubs: a stub coordinate_heal_target returning a fixed regen-target, a stub classifier that writes one coordinate via write_coordinate_map, and ONE route_walk wiring hop, so migration_coverage(fixture).unmigrated_in_range reaches 0 end-to-end. Stubs are replaced section-by-section downstream.

Fresh intel (regenerated)

{ “schema_version”: 1, “target”: { “kind”: “plan-section”, “ref”: “ledger-coordinate-migration/s-1712f55b” }, “generated_at”: “2026-06-29T20:10:16.431774+00:00”, “graph_state”: { “head_sha”: “72ec9529”, “last_code_import_at”: “2026-06-29T20:05:32.635Z”, “embedding_stale”: true, “insights_stale”: false, “cpg_stale”: false }, “surfaces”: {}, “summary”: “intel-package[plan-section:ledger-coordinate-migration/s-1712f55b] agent-authored dossier”, “degraded”: false, “dossier”: { “objective_symbols”: [], “tiers”: {}, “agent_authored”: true, “constrained_symbols”: [ “validate_ledger_append_only”, “assemble_corpus”, “read_ranked”, “_FORBIDDEN_REFERENCES”, “compose_dead_ends_ledger” ], “difficulty”: { “class”: “routine”, “research_online”: false, “research_mode”: “auto”, “signals”: [], “plan_dir”: “/home/eric/projects/ori_lang/plans/ledger-coordinate-migration” } } }

(full dossier: walking-skeleton—s-1712f55b.intel.json)