rnd(M03): introduce renderer facade seam

Work-Package: M03-RND-FACADE-001
Agent: sindo-main-codex
Tests: facade/focus/coordinate/manifest contracts, renderer dry-run, coordination and documentation gates
Fidelity: focus targets, budgets, queues, caches and visible renderer behavior remain unchanged

docs/modules/world-renderer.md

@@ -5,9 +5,9 @@
 | Field | Value |
 |---|---|
 | Status | Partial |
-| Target/work package | M00 baseline; `M01-RND-STREAMING-FOCUS-001`; `M01-QAR-SERVER-SPAWN-RENDERER-001`; декомпозиция M02–M03 |
+| Target/work package | M00 baseline; `M01-RND-STREAMING-FOCUS-001`; `M01-QAR-SERVER-SPAWN-RENDERER-001`; `M03-RND-FACADE-001` |
 | Owners | Renderer workstream / milestone integrator |
-| Last verified | Worktree `work/sindo-main-codex/m01-server-spawn-renderer`, 2026-07-13 |
+| Last verified | Worktree `work/sindo-main-codex/m03-renderer-facade`, 2026-07-15 |
 | Profiles/capabilities | `Performance`, `Balanced`, `High`, `Custom`; Blizzlike fidelity incomplete |
 
 ## Purpose
@@ -32,7 +32,8 @@ flowchart LR
     SpawnFixture[Pinned server spawn fixture] --> SpawnManifest[Spawn render manifest]
     SpawnManifest --> Capture
     Adapter --> Focus
-    Focus --> Loader[StreamingWorldLoader]
+    Focus --> Facade[WorldRenderFacade]
+    Facade --> Loader[StreamingWorldLoader internal]
     Assets[Extracted WDT/ADT/M2/WMO/BLP] --> Native[Native loaders]
     Cache[Baked terrain/M2/WMO caches] --> Loader
     Native --> Parsed[Parsed tile/model data]
@@ -60,36 +61,43 @@ Forbidden dependencies:
 
 ## Public API
 
-Текущая система ещё не имеет стабильного facade. Фактический integration surface — `StreamingWorldLoader` Node3D и exported properties. M03 должен заменить этот surface на `WorldRenderFacade`.
+Runtime, capture and probe callers use `WorldRenderFacade` for focus and metrics.
+`StreamingWorldLoader` remains the internal scene implementation while later M03
+packages add environment, entity-visual and ground-query contracts.
 
 | Symbol | Kind | Purpose | Thread/lifetime | Errors |
 |---|---|---|---|---|
 | `map_name` | Exported property | WDT/map directory name | Set before world load | Missing WDT produces diagnostic/empty world |
 | `extracted_dir` | Exported property | Root of legally extracted client data | Session lifetime | Missing files reported per loader path |
 | `StreamingFocus` | Immutable value | Typed Godot-basis position without Node/Camera dependency | Any thread; caller-owned reference | Null position is a caller contract violation |
-| `streaming_focus_source_path` | Exported adapter property | Samples any explicit `Node3D` source into `StreamingFocus` | Main thread, scene lifetime | Missing/wrong node warns once and retains prior focus |
-| `set_streaming_focus` | Public method | Accepts focus from app/editor/tool composition | Main thread/session | Null focus is ignored by refresh until replaced |
-| `refresh_streaming_focus` | Public method | Samples configured source and applies refresh thresholds | Main thread/session | Returns `false` when no valid focus exists |
+| `WorldRenderFacade.streaming_focus_source_path` | Exported adapter property | Samples any explicit `Node3D` source into `StreamingFocus` | Main thread, scene lifetime | Missing/wrong node warns once and retains prior focus |
+| `WorldRenderFacade.set_streaming_focus` | Public method | Accepts focus from app/editor/tool composition | Main thread/session | Missing internal renderer is diagnosed; no state is duplicated |
+| `WorldRenderFacade.refresh_streaming_focus` | Public method | Samples configured source and delegates existing refresh thresholds | Main thread/session | Returns `false` when dependency/focus is unavailable |
+| `WorldRenderFacade.renderer_metrics_snapshot` | Public method | Returns a deep-detached queue/cache/activity snapshot | Main thread/caller-owned result | Missing/invalid implementation result returns empty snapshot with diagnostic |
+| `WorldRenderFacade.streaming_world_loader_path` | Internal adapter property | Resolves the existing implementation without exposing it to consumers | Main thread, scene lifetime | Missing method/path produces one diagnostic until recovery |
 | `camera_path` | Exported property | Camera used only by optional automatic overview positioning | Main thread, scene lifetime | Missing camera skips automatic positioning |
 | `quality_preset` | Exported property | Applies renderer budgets/radii | Before/at runtime depending property | Invalid combination should be diagnosed |
 | `runtime_stats_enabled` | Exported property | Enables periodic performance snapshot | Runtime mutable | Logging overhead only |
 | `hitch_profiler_enabled` | Exported property | Enables named hitch sections | Runtime mutable | Logging overhead only |
 
-Публичным contract не считаются внутренние dictionaries, queues, job records и generated node names.
+Публичным contract не считаются `StreamingWorldLoader` methods/properties,
+внутренние dictionaries, queues, job records и generated node names. Scene-owned
+loader configuration remains transitional composition data, not a caller API.
 
 ## Inputs and outputs
 
 | Direction | Contract/data | Producer | Consumer | Ownership | Thread/lifetime |
 |---|---|---|---|---|---|
-| Input | `StreamingFocus` | Player/spectator/editor/capture adapter | `StreamingWorldLoader` | Immutable caller value | Main thread/session |
-| Input | Focus-source `NodePath` | Runtime/test scene composition | Loader source adapter | Scene-owned node, sampled position | Main thread/scene lifetime |
+| Input | `StreamingFocus` | Player/spectator/editor/capture adapter | `WorldRenderFacade` | Immutable caller value | Main thread/session |
+| Input | Focus-source `NodePath` | Runtime/test scene composition | `WorldRenderFacade` source adapter | Scene-owned node, sampled position | Main thread/scene lifetime |
 | Input | Map/configuration | Scene/app/editor | `StreamingWorldLoader` | Caller config, copied/read | Main thread/session |
 | Input | WDT/ADT/M2/WMO/BLP bytes | Extracted asset repository | Native loaders/builders | Loader result owns parsed data | Worker or controlled load |
 | Input | Baked resources | Cache build tools | Streamer/builders | Shared immutable resource/cache entry | Session/cache lifetime |
 | Test input | Server-spawn render manifest | Coordinate fixture/verifier | Checkpoint capture tool | Repository-owned diagnostic data | Test-process lifetime |
 | Output | Desired tile/detail operations | Streaming planner inside loader | Finalize queues | Loader-owned | Cross-frame |
 | Output | Terrain/M2/WMO/liquid instances | Loader/builders | Godot world/renderer | Loader/world owner | Main-thread attach |
-| Output | Metrics/diagnostics | Hitch/stat instrumentation | Logs/baseline tools | Immutable records | Periodic/frame |
+| Output | Detached renderer metrics | `WorldRenderFacade` | Capture/baseline tools | Caller-owned deep copy | On demand |
+| Output | Logs/diagnostics | Hitch/stat instrumentation | Logs/baseline tools | Immutable records | Periodic/frame |
 | Test output | Diagnostic spawn marker and cold/warm PNGs | Checkpoint capture tool | Human/integrator review | SceneTree marker; `user://` files | One capture process |
 
 Side effects:
@@ -104,7 +112,7 @@ Side effects:
 
 ```mermaid
 flowchart TD
-    P[Player/spectator Node3D] --> A[Explicit scene adapter]
+    PlayerSource[Player/spectator Node3D] --> A[Explicit scene adapter]
     C[Capture camera] --> A
     SF[Pinned server spawn] --> SM[Validated spawn manifest]
     SM --> C
@@ -112,11 +120,12 @@ flowchart TD
     E[Editor viewport] --> EA[Editor adapter]
     A --> F[StreamingFocus]
     EA --> F
-    F --> T[Compute desired ADT tiles]
+    F --> RF[WorldRenderFacade]
+    RF --> T[StreamingWorldLoader target refresh]
     WDT[WDT tile catalog] --> T
     T --> Q[Tile load queue]
-    Q --> P[Worker parse/cache load]
-    P --> R[Result queues]
+    Q --> Parse[Worker parse/cache load]
+    Parse --> R[Result queues]
     R --> B[Per-frame budget scheduler]
     B --> Terrain[Terrain attach/upgrade]
     B --> M2[M2 group/MultiMesh attach]
@@ -155,12 +164,14 @@ stateDiagram-v2
 sequenceDiagram
     participant Source as Player/Editor/Capture source
     participant Focus as StreamingFocus adapter
-    participant Stream as StreamingWorldLoader
+    participant Facade as WorldRenderFacade
+    participant Stream as StreamingWorldLoader internal
     participant Worker as Worker task
     participant Budget as Main-thread budget
     participant Render as SceneTree/RenderingServer
     Source->>Focus: sample explicit Godot position
-    Focus->>Stream: set/refresh typed focus
+    Focus->>Facade: set/refresh typed focus
+    Facade->>Stream: delegate focus and refresh
     Stream->>Stream: desired tiles and priorities
     Stream->>Worker: parse/load tile and detail data
     Worker-->>Stream: immutable result
@@ -176,6 +187,8 @@ sequenceDiagram
 ## Ownership, threading and resources
 
 - `StreamingWorldLoader` владеет tile states, queues, task registries, active world instances и render caches session scope.
+- `WorldRenderFacade` owns only scene-relative adapter paths. It does not own the
+  streamer, focus source, returned metrics, queues, caches, nodes or RIDs.
 - Focus producers own the immutable `StreamingFocus` reference; the loader retains
   the latest reference and converts it to `Vector3` only inside the render boundary.
 - Worker tasks не должны менять SceneTree и shared Resource concurrently.
@@ -192,6 +205,8 @@ sequenceDiagram
 |---|---|---|---|---|
 | Missing WDT/ADT | File/catalog check | Tile/map unavailable | Loader warning/error | Fix extraction/profile, reload |
 | Missing focus source | Explicit NodePath resolution | Retain current streamed content and prior valid focus | One warning until source recovers | Fix composition path or call `set_streaming_focus` |
+| Missing renderer implementation | Facade path/method validation | Focus/metrics call fails without mutation | One facade diagnostic until recovery | Fix scene composition path/implementation |
+| Invalid metrics result | Facade return-type validation | Return empty caller snapshot | Facade error | Restore `Dictionary` implementation contract |
 | No focus supplied | Refresh contract | No target recomputation; queues continue draining | `refresh_streaming_focus()` returns `false` | Supply player/editor/capture focus |
 | Cache version mismatch | Required format constant | Reject stale cache/fallback | Version diagnostic | Rebuild matching cache |
 | Worker failure | Task result/empty data | Skip/degrade affected asset | Queue/task warning | Retry/rebuild source |
@@ -225,6 +240,8 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 ## Diagnostics and observability
 
 - Logs: `HITCH`, `PERF`, `TERRAIN_QUALITY`, `SKY_LIGHT`, `SKYBOX_MODEL`.
+- API snapshot: `WorldRenderFacade.renderer_metrics_snapshot()` returns detached
+  queue/cache/activity counts without exposing mutable renderer state.
 - Metrics: queue depths, active tiles/assets, named finalize times, frame percentiles and max hitch.
 - Debug views: render checkpoint scenes/captures; future streaming/LOD/portal overlays.
 - Correlation IDs: currently mostly tile/path keys; target architecture adds session/job IDs.
@@ -257,7 +274,7 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | Character presentation | Prototype | Character creator/player experiment | Full customization/equipment states |
 | Camera-independent streaming focus | Implemented | Typed contract, two player-focused runtime scenes and three explicitly camera-focused diagnostic tools | Multi-focus/direction/velocity belong to planner extraction |
 | Golden server-spawn visualization | Implemented | Pinned AzerothCore fixture, validated renderer manifest and diagnostic origin-marker capture at ADT `(32,48)`/MCNK `(3,12)` | No TrinityCore row or original-client visual-parity claim |
-| Stable renderer facade | Planned | M03 | Current caller uses monolithic Node API |
+| Stable renderer facade | Partial | `M03-RND-FACADE-001` contract/runtime/tool regressions | Focus and metrics migrated; environment/entity visuals/ground query remain |
 
 ## Known gaps and risks
 
@@ -283,9 +300,11 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 
 | Path | Responsibility |
 |---|---|
+| `src/render/world_render_facade.gd` | Stable caller boundary for typed focus and detached renderer metrics |
 | `src/scenes/streaming/streaming_world_loader.gd` | Current runtime orchestration, queues, caches and attachment |
 | `src/domain/streaming/streaming_focus.gd` | Immutable camera-independent streaming position contract |
 | `src/tools/verify_streaming_focus.gd` | Headless contract, dependency and runtime/tool wiring regression |
+| `src/tools/verify_world_render_facade.gd` | Facade delegation, snapshot isolation and consumer wiring regression |
 | `addons/mpq_extractor/loaders/adt_builder.gd` | Terrain/material/liquid construction |
 | `addons/mpq_extractor/loaders/m2_builder.gd` | Static M2 mesh/material construction |
 | `addons/mpq_extractor/loaders/m2_native_animated_builder.gd` | Native animated M2 experiment |