test(M03): enforce streamer internal access boundary

RENDER.md

@@ -919,6 +919,21 @@ $exe = Join-Path $env:TEMP 'godot-4.6.1-openwc\Godot_v4.6.1-stable_win64.exe'
 - Defaults, quality presets, queue order, cache versions and visible rendering
   rules are unchanged. Asset-backed p95/p99 comparison remains required.
 
+## 2026-07-16 Streamer Internal Access Gate
+
+- `verify_renderer_internal_access.gd` derives private queue, task, cache and
+  tile-state field names from `StreamingWorldLoader` declarations and rejects
+  external member/reflection access in gameplay and Godot `EditorPlugin` package sources.
+- The gate follows the implementation inventory instead of duplicating a manual
+  list, so a newly named private renderer field is covered automatically when it
+  matches those ownership categories.
+- Scene composition may still reference the loader script and the facade's
+  implementation path; those are composition details, not mutable queue access.
+- Renderer diagnostic probes are outside this gameplay/editor checklist.
+  `probe_render_terrain_height.gd` remains a documented temporary exception until
+  readiness and ground-query facade contracts replace its internal inspection.
+- This is a source-only boundary check and changes no renderer behavior or fidelity.
+
 ## Practical Rule For Future Work
 
 If something improves quality but creates visible hitch, it is not done. Move it to bake/cache/background work, split finalization over frames, or prewarm it before the player can see it.