coord(M03): claim M2 placement transform resolver

coordination/claims/M03-RND-M2-PLACEMENT-TRANSFORM-001.md

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+# M03-RND-M2-PLACEMENT-TRANSFORM-001 — M2 placement transform resolver
+
+<!-- OPENWC_CLAIM:M03-RND-M2-PLACEMENT-TRANSFORM-001:sindo-main-codex:2026-07-19 -->
+
+## Ownership
+
+- Target: M03
+- Program: RND
+- Owner/Agent ID: sindo-main-codex
+- Branch: `work/sindo-main-codex/m03-m2-placement-transform`
+- Lease expires UTC: 2026-07-19
+- Integrator: M03 milestone integrator
+
+## Outcome
+
+Extract pure ADT M2 placement basis/origin-offset calculation, including the
+existing waterfall and Elwynn cliff-rock calibrations, into a scene-free service.
+
+## Non-goals
+
+- Change coordinate conversion, placement positions, rotations or scale clamps.
+- Generalize model-specific corrections or add new allowlisted models.
+- Move grouping/tasks, MultiMesh/Node/Mesh/material/RID creation or caches.
+- Change M2 animation/material behavior, cache versions or renderer profiles.
+- Claim build-12340 placement parity beyond existing fixtures.
+
+## Paths
+
+- Exclusive: `src/render/m2/m2_placement_transform_resolver.gd`,
+  `src/tools/verify_m2_placement_transform_resolver.gd`,
+  `docs/modules/m2-placement-transform-resolver.md`, this claim
+- Shared/hotspots: `src/scenes/streaming/streaming_world_loader.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
+  proprietary renderer corpus
+
+## Contracts and data
+
+- Input: ADT-loader Godot Euler rotation, normalized/original M2 relative path,
+  and raw placement scale where origin compensation is requested
+- Output: `Basis` and local origin-offset `Vector3`; no retained state
+- Regular models use `Basis.from_euler`; two cliff rocks retain narrow YZX-style
+  shell correction; two waterfall sheets retain yaw/twist/anchor compensation
+- Scale clamps remain caller-owned for final basis and resolver-owned at `0.0001`
+  only for historical waterfall anchor compensation
+- Cache/schema/coordinate versions: unchanged
+
+## Dependencies
+
+- Requires: current master `1b6c468`
+- Blocks: pure M2 grouping extraction and broader M2 service decomposition
+- External state: none; tests use synthetic rotations/paths and pinned constants
+
+## Verification
+
+- Commands: dedicated regular/path-normalization/cliffrock/waterfall/twist-anchor/
+  scale and bounded timing verifier; three loader call-site/source boundaries;
+  M2 unique/dedupe plus facade/terrain/internal-access/manifest/shutdown gates
+- Fidelity evidence: exact formulas/constants and model allowlists moved unchanged
+- Performance budget: allocation-free scalar/Basis math per placement aside from
+  path normalization; no Node, Resource, RID, task, cache or file access
+
+## Documentation deliverables
+
+- Inline resolver API documentation
+- New module spec with inputs/outputs, data-flow, lifecycle, ownership, failure,
+  performance, fidelity limitations and source map
+- World renderer/module registry/`RENDER.md` updates
+
+## Simplicity and naming
+
+- Important name: `M2PlacementTransformResolver`
+- Simplest solution: stateless service with basis and origin-offset queries
+- Rejected complexity: transform strategy hierarchy, generic correction registry,
+  Resources, data-driven override format or callback injection
+- Unavoidable complexity: four measured model-specific exceptions remain explicit
+- Measured optimization evidence: bounded synthetic transform loop
+
+## Status
+
+- State: claimed
+- Done: scope, formulas, allowlists and ownership published
+- Next: implement resolver, migrate three call sites, tests and docs
+- Blocked by:
+
+## Handoff
+
+- Commit:
+- Results:
+- Remaining risks:
+- Documentation updated: