docs(coordination): hand off M2 unique registry

coordination/claims/M03-RND-M2-UNIQUE-REGISTRY-001.md

@@ -30,6 +30,7 @@ streamer into a scene-free `M2UniquePlacementRegistry`.
   `src/tools/verify_m2_unique_placement_registry.gd`,
   `docs/modules/m2-unique-placement-registry.md`, this claim
 - Shared/hotspots: `src/scenes/streaming/streaming_world_loader.gd`,
+  `src/tools/verify_m2_unique_dedupe.gd`,
   `docs/modules/world-renderer.md`, `docs/modules/README.md`, `RENDER.md`,
   `targets/03-renderer-facade.md`
 - Generated/ignored: `.godot`, native DLL, generated ADT resources, caches and
@@ -77,14 +78,23 @@ streamer into a scene-free `M2UniquePlacementRegistry`.
 
 ## Status
 
-- State: claimed
-- Done: scope, key semantics and ownership published
-- Next: implement registry, migrate loader adapters, tests and docs
+- State: handoff
+- Done: stateful registry, loader adapters, migrated smoke, regressions and docs
+- Next: milestone integrator merge and asset-backed boundary traversal later in M03
 - Blocked by:
 
 ## Handoff
 
-- Commit:
-- Results:
-- Remaining risks:
-- Documentation updated:
+- Commit: `acb3a80` (`refactor(M03): extract M2 unique placement registry`)
+- Results: dedicated contract PASS (`cases=10`, `iterations=100`, `35.688 ms`);
+  historical `uid:11785` smoke PASS; terrain/facade/internal-access/manifest/
+  shutdown/scheduler/streaming/focus/terrain-query/coordinate regressions PASS;
+  internal inventory remains `42`; editor parse and documentation/coordination/
+  diff gates PASS; checkpoint dry-run planned `7/7`
+- Remaining risks: private Azeroth corpus was absent, so the asset-backed ADT
+  placement probe could not open the map and is not counted as passed evidence;
+  first ownership remains processing-order based; M2 grouping/build/tasks/caches/
+  finalization and asset-backed p95/p99 remain pending
+- Documentation updated: `m2-unique-placement-registry.md`, module registry,
+  `world-renderer.md`, `RENDER.md`, inline API documentation and data-flow,
+  lifecycle and sequence diagrams