refactor(M03): extract WMO render build planner

docs/modules/world-renderer.md

@@ -7,7 +7,7 @@
 | Status | Partial |
 | Target/work package | M00 baseline; `M01-RND-STREAMING-FOCUS-001`; `M01-QAR-SERVER-SPAWN-RENDERER-001`; M03 facade/planner/scheduler/internal-access/ground/environment/entity packages; M03 terrain packages; M03 M2 packages; M03 WMO placement package |
 | Owners | Renderer workstream / milestone integrator |
-| Last verified | Worktree `work/sindo-main-codex/m03-wmo-placement-registry`, 2026-07-17 |
+| Last verified | Worktree `work/sindo-main-codex/m03-wmo-render-build-planner`, 2026-07-17 |
 | Profiles/capabilities | `Performance`, `Balanced`, `High`, `Custom`; Blizzlike fidelity incomplete |
 
 ## Purpose
@@ -58,6 +58,8 @@ flowchart LR
     WmoPlacement --> Loader
     Loader --> WmoRegistry[WmoPlacementRegistry]
     WmoRegistry --> Loader
+    Loader --> WmoBuildStep[WmoRenderBuildStepPlanner]
+    WmoBuildStep --> Loader
     Native --> Parsed[Parsed tile/model data]
     Parsed --> Loader
     Loader --> Scene[SceneTree nodes]
@@ -130,6 +132,7 @@ from externally reading/writing loader-private queue, task, cache and tile-state
 | `M2BuildBatchPlanner.plan_batch` | Internal pure M2 service | Selects static/animated batch count and next group cursor | Main/any thread; stateless | Non-positive selected limit clamps to one; empty range completes |
 | `WmoPlacementResolver.normalize_relative_path/resolve_unique_key/resolve_world_transform` | Internal pure WMO service | Resolves cache key, registry identity and world transform | Main/any thread; stateless | Missing UID uses tile/index fallback; transform fields use historical defaults |
 | `WmoPlacementRegistry.add_reference/release_reference/contains/active_count/diagnostic_snapshot/clear` | Internal WMO service | Owns placement-key to tile/global reference sets | Renderer main thread; map session | Empty/unknown/non-owner input is rejected without mutation |
+| `WmoRenderBuildStepPlanner.plan_step` | Internal pure WMO service | Selects one mesh-first lightweight render-group operation and next cursors | Main/any thread; stateless | Raw integer comparisons are preserved without clamping |
 
 Публичным contract не считаются `StreamingWorldLoader` methods/properties,
 внутренние dictionaries, queues, job records и generated node names. Scene-owned
@@ -160,6 +163,7 @@ loader configuration remains transitional composition data, not a caller API.
 | Internal batch plan | Transform count/offset, path kind and limits | Loader / `M2BuildBatchPlanner` | Loader materialization/cursor adapter | Fresh scalar Dictionary | One build operation |
 | Internal WMO placement | Path, MODF placement, tile/index | Loader / `WmoPlacementResolver` | WMO caches, registry and three instance adapters | Value-only String/Transform3D | Lookup/placement lifetime |
 | Internal WMO ownership | Resolved placement key and tile/global reference key | Loader / `WmoPlacementRegistry` | Loader create/retain/final-free decisions | Registry-owned String sets; detached diagnostics | Map session or final release |
+| Internal WMO build step | Mesh/MultiMesh counts and job cursors | Loader / `WmoRenderBuildStepPlanner` | Loader materialization/cursor adapter | Fresh scalar Dictionary | One group operation |
 | Output | Desired tile/detail operations | Streamer plan application | Finalize queues | Loader-owned | Cross-frame |
 | Output | Terrain/M2/WMO/liquid instances | Loader/builders | Godot world/renderer | Loader/world owner | Main-thread attach |
 | Output | Detached renderer metrics | `WorldRenderFacade` | Capture/baseline tools | Caller-owned deep copy | On demand |
@@ -210,7 +214,8 @@ flowchart TD
     M2Batch --> M2
     R --> WmoPlacement[WmoPlacementResolver]
     WmoPlacement --> WmoRegistry[WmoPlacementRegistry]
-    WmoRegistry --> WMO
+    WmoRegistry --> WmoBuildStep[WmoRenderBuildStepPlanner]
+    WmoBuildStep --> WMO
     R --> B[RenderBudgetScheduler permits]
     B --> Terrain[Terrain attach/upgrade]
     B --> M2[M2 group/MultiMesh attach]
@@ -334,8 +339,9 @@ sequenceDiagram
   loader retains queue/resource transitions, cursor adoption and materialization.
 - `WmoPlacementResolver` is stateless and owns only call-local cache-key,
   identity and transform values. `WmoPlacementRegistry` owns only placement-key
-  reference sets. The loader retains the key-to-Node map, caches, jobs, queues,
-  resources, cancellation and every Node lifecycle action.
+  reference sets. `WmoRenderBuildStepPlanner` owns only a call-local operation
+  and cursor plan. The loader retains the key-to-Node map, caches, jobs, queues,
+  resources, cursor adoption, permits, cancellation and every Node lifecycle action.
 - Rendered-ground query results and diagnostic snapshots are caller-owned values;
   the facade never returns Mesh, Node, tile-state or queue references.
 - Loaded-mesh ground sampling is renderer diagnostics, not authoritative gameplay
@@ -431,6 +437,8 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
   default/rotated/unclamped transforms, three consumers and bounded timing.
 - WMO placement registry contract: first/idempotent/shared/non-owner/final/global
   lifecycle, detached sorted diagnostics, source ownership and bounded timing.
+- WMO render build step contract: mesh-before-MultiMesh order, one-index cursor
+  transition, completion/raw integer behavior, source ownership and bounded timing.
 - Budget scheduler contract: exact lane exhaustion, shared chunk removal/create
   priority, independent lanes, frame reset, invalid limits, terminal cancellation,
   dependency boundaries and bounded permit timing without loading a world scene.
@@ -466,6 +474,7 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | M2 build batch planner | Implemented extraction | Scene-free limit/count/cursor/source/timing contract | Queue/resource state, spatial cells and asset-backed p95/p99 remain pending |
 | WMO placement resolver | Implemented extraction | Scene-free path/identity/transform/source/timing contract | Asset-backed comparison pending |
 | WMO placement registry | Implemented extraction | Scene-free ownership/lifecycle/source/timing contract | Build/resource state and asset-backed cross-tile corpus pending |
+| WMO render build step planner | Implemented extraction | Scene-free order/cursor/source/timing contract | Job/resource ownership and asset-backed traversal p95/p99 pending |
 | WMO rendering | Partial | Cached group rendering | Portals/rooms/material parity |
 | Liquids | Partial | MH2O/MLIQ paths | LiquidType/depth/shore fidelity |
 | Sky/light | Partial | DBC controller/logs | Zone transition paired validation |