refactor(M03): extract M2 runtime rebuild classifier

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-adt-water-scene-finalizer`, 2026-07-17 |
+| Last verified | Worktree `work/sindo-main-codex/m03-m2-runtime-rebuild-classifier`, 2026-07-17 |
 | Profiles/capabilities | `Performance`, `Balanced`, `High`, `Custom`; Blizzlike fidelity incomplete |
 
 ## Purpose
@@ -132,6 +132,7 @@ from externally reading/writing loader-private queue, task, cache and tile-state
 | `M2PlacementTransformResolver.resolve_basis/resolve_origin_offset` | Internal pure M2 service | Resolves regular and calibrated model-specific ADT placement transforms | Worker/main thread; stateless | Unknown paths use regular basis and zero offset |
 | `M2PlacementGrouper.group_placements` | Internal pure M2 service | Validates and groups ordered tile-local placement transforms by normalized path | Worker/main thread; stateless | Invalid variants/name IDs/empty paths are skipped |
 | `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 |
+| `M2RuntimeMeshRebuildClassifier` | Internal memoized M2 service | Detects billboard/UV-rotation metadata requiring stale cached-mesh rebuild | Renderer main thread; cached until reset | Invalid variants/indices skipped; first path decision wins |
 | `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 |
@@ -365,6 +366,9 @@ sequenceDiagram
   stale tile/path/root checks and `water_loaded` timing. `AdtWaterSceneFinalizer`
   performs the existing ADTBuilder call, tile attach and optional recursive
   Editor ownership on the main thread without retaining the generated subtree.
+- `M2RuntimeMeshRebuildClassifier` owns only normalized-path boolean decisions
+  for billboard/UV-rotation material refresh. The loader retains raw M2 loading,
+  refresh-version checks, Mesh rebuild/adoption and both historical clear sites.
 - 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
@@ -565,6 +569,7 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | `src/render/terrain/terrain_quality_mesh_cache.gd` | Full-quality terrain revisit Mesh retention and LRU ownership |
 | `src/render/liquid/adt_water_load_pipeline_state.gd` | ADT water request/task/result bookkeeping and worker-safe mailbox |
 | `src/render/liquid/adt_water_scene_finalizer.gd` | Main-thread ADT water build, tile attachment and optional editor ownership |
+| `src/render/m2/m2_runtime_mesh_rebuild_classifier.gd` | Billboard/UV-rotation stale cached-mesh rebuild decision and memoization |
 | `src/render/streaming/streaming_target_planner.gd` | Scene-free wanted/retained ADT target calculation |
 | `src/render/streaming/streaming_target_policy.gd` | Immutable renderer radius/prefetch policy |
 | `src/render/streaming/streaming_target_plan.gd` | Immutable planner result with read-only tile-key sets |
@@ -579,6 +584,7 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | `src/tools/verify_terrain_quality_mesh_cache.gd` | Terrain cache admission, LRU, ownership and loader-boundary regression |
 | `src/tools/verify_adt_water_load_pipeline_state.gd` | ADT water FIFO/task/thread/boundary/timing regression |
 | `src/tools/verify_adt_water_scene_finalizer.gd` | Synthetic ADT water scene/ownership/boundary/timing regression |
+| `src/tools/verify_m2_runtime_mesh_rebuild_classifier.gd` | M2 rebuild predicate/cache/boundary/timing regression |
 | `src/tools/verify_streaming_target_planner.gd` | Planner behavior, dependency and bounded timing regression |
 | `src/tools/verify_render_budget_scheduler.gd` | Scheduler bounds, shared-lane priority, cancellation and timing regression |
 | `src/tools/verify_renderer_internal_access.gd` | Gameplay/EditorPlugin/registered renderer-tool boundary gate derived from private streamer fields |