feat(M01): enforce coordinate conversion boundaries

Work-Package: M01-FND-COORD-BOUNDARY-GATE-001

Agent: sindo-main-codex

docs/adr/0001-canonical-world-coordinates.md

@@ -108,6 +108,21 @@ show `indexX` decreasing world Y (east) and `indexY` decreasing world X (south).
 OpenRealm independently calculates filename X from world Y and filename Y from
 world X. Contract version 2 corrects the formulas before any consumer migration.
 
+### Enforced conversion boundaries
+
+GDScript production consumers use `CoordinateMapper` for canonical/Godot and
+Godot/ADT tile-local conversion. `StreamingWorldLoader`, player spawn/terrain
+sampling, sky/area lookup and terrain diagnostics may construct `Vector3` only
+at their scene/tool boundary.
+
+The native ADT/WDT parser path retains one equivalent formula definition in
+`src/native/src/wow_chunk_reader.h`; worker parsers cannot call GDScript. The
+M00 renderer calibration keeps one independent formula as a test oracle so a
+shared mapper defect cannot make both implementation and evidence agree.
+Repository verification rejects additional world-center, world/tile or named
+WoW/Godot formulas outside those explicit exceptions. Model-local M2/WMO basis
+transforms are separate format contracts and are not classified as world-space mapping.
+
 ## Alternatives considered
 
 ### Make renderer coordinates canonical
@@ -138,10 +153,12 @@ grid ownership rules.
 - Renderer consumers must explicitly map and then create Godot vectors at their
   own boundary.
 - ADT filename indices can no longer be confused with renderer X/Z tile names.
-- Existing native/parser and renderer conversions remain unchanged until
-  separate consumer migration packages merge after this contract.
-- Manual axis conversions become review/test violations once migration is
-  complete; this ADR alone does not delete compatibility paths.
+- GDScript world/tile consumers use mapper APIs; renderer distance and LOD math
+  remains ordinary Godot-space geometry.
+- Native ADT/WDT loaders share one boundary formula and the M00 calibration
+  keeps one independent non-production oracle.
+- New manual axis conversions are review/test violations enforced by the
+  repository-wide source gate.
 - Persisted schemas are unchanged. Future serialized positions must include an
   explicit coordinate-space/version discriminator.
 
@@ -154,6 +171,8 @@ grid ownership rules.
 - The observed Elwynn position resolves to the real `Azeroth_31_49.adt` file;
   MCNK `(0,0)` to `(15,15)` origins confirm X-east and Y-south chunk growth.
 - World-yaw normalization and round-trip cases cover cardinal angles and wrap.
+- Direct Godot/ADT tile-local conversions round-trip and production consumers
+  are checked by `verify_coordinate_conversion_boundaries.gd`.
 
 ## References