docs(M01): claim ADT tile axis correction

Work-Package: M01-FND-COORD-TILE-AXIS-002
Agent: sindo-main-codex
Tests: not applicable (claim only)
Fidelity: raw Azeroth_31_49 ADT and OpenRealm independently expose swapped filename axes

coordination/claims/M01-FND-COORD-TILE-AXIS-002.md

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+# M01-FND-COORD-TILE-AXIS-002 — ADT filename axis correction
+
+<!-- OPENWC_CLAIM:M01-FND-COORD-TILE-AXIS-002:sindo-main-codex:2026-07-15 -->
+
+## Ownership
+
+- Target: M01
+- Program: FND
+- Owner/Agent ID: sindo-main-codex
+- Branch: `work/sindo-main-codex/m01-coordinate-tile-axis-fix`
+- Lease expires UTC: 2026-07-15
+- Integrator: M01 milestone integrator
+
+## Outcome
+
+Correct the additive coordinate contract so `AdtTileCoordinate(tile_x, tile_y)`
+matches actual `Map_tileX_tileY.adt` filenames and MCNK `indexX/indexY` axes.
+
+## Non-goals
+
+- Migrating renderer/native consumers.
+- Changing canonical, server, Godot or ADT placement position arithmetic.
+- Adding server-spawn fixtures or `StreamingFocus`.
+- Committing proprietary ADT bytes.
+
+## Paths
+
+- Exclusive: `src/domain/coordinates/coordinate_mapper.gd`,
+  `src/domain/coordinates/adt_chunk_coordinate.gd`,
+  `src/tools/verify_coordinate_mapper.gd`
+- Shared/hotspots: `docs/adr/0001-canonical-world-coordinates.md`,
+  `docs/modules/coordinate-mapping.md`, this claim
+- Generated/ignored: local extracted ADT and Godot import metadata
+
+## Contracts and data
+
+- Public API/events: method names unchanged; corrected tile/chunk axis semantics
+- Schema/format version: coordinate contract version increments from 1 to 2
+- Migration/compatibility: no released consumer exists; contract was merged but
+  not yet consumed, so correction precedes consumer rollout
+- Consumers: future renderer, network, gameplay and server-data adapters
+
+## Dependencies
+
+- Requires: merged `M01-FND-COORDS-001` at `1c0dfc7`
+- Blocks: coordinate golden fixtures and all coordinate consumers
+- External state: private `Azeroth_31_49.adt` used read-only for evidence
+
+## Verification
+
+- Commands: coordinate mapper probe, M00 calibration, manifest, documentation
+  and coordination gates
+- Fixtures: build 12340 Elwynn point must resolve to `Azeroth_31_49.adt`;
+  MCNK `(0,0)` and `(15,15)` establish chunk-axis direction
+- Fidelity evidence: local ADT SHA-256
+  `18185B5FAC9566D9C57A9C19ABD75F108370D1795639B6077167C0EFD3672FAE`;
+  OpenRealm independently indexes filename X from world Y and filename Y from world X
+- Performance budget: unchanged constant-time scalar arithmetic
+
+## Documentation deliverables
+
+- Inline public API docs: corrected tile/chunk direction comments
+- Module specification: contract version, formulas, capability evidence and risk
+- Data-flow diagram: corrected filename/chunk axes
+- ADR: corrected decision and evidence
+- Sequence/state diagrams: not applicable; pure synchronous mapper
+
+## Simplicity and naming
+
+- Important names introduced: none
+- Simplest considered solution: swap the two filename formulas and corresponding
+  local/chunk ownership calculations
+- Rejected complexity/abstractions: compatibility flag for a contract with no consumers
+- Unavoidable complexity and justification: ADT filename axes differ from client X/Y order
+- Measured optimization evidence: not applicable
+
+## Status
+
+- State: active
+- Done: raw-corpus and independent-reference diagnosis
+- Next: regression test, mapper correction and documentation update
+- Blocked by: