docs: update STATUS.md and DEFERRED.md with scene viewport

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/DEFERRED.md

@@ -146,7 +146,7 @@
 
 ## Phase 8-4
 
-- **씬 뷰포트** — 3D 렌더러 임베드 미구현.
+- ~~**씬 뷰포트**~~ ✅ 오프스크린 렌더링 + 오빗 카메라 완료. Blinn-Phong forward만 (디퍼드/PBR 미지원).
 - **엔티티 인스펙터** — ECS 컴포넌트 편집 미구현.
 - **에셋 브라우저** — 파일 시스템 탐색 미구현.
 - ~~**텍스트 입력**~~ ✅ text_input 위젯 완료.

docs/STATUS.md

@@ -122,6 +122,7 @@
 - voltex_editor: Widgets (text, button, slider, checkbox, panel, text_input, scroll_panel)
 - voltex_editor: Drag and Drop (begin_drag, drop_target)
 - voltex_editor: DockTree (binary split layout, resize, tab switching)
+- voltex_editor: OrbitCamera, ViewportTexture, ViewportRenderer (3D scene viewport)
 - examples/editor_demo
 
 ## Crate 구조
@@ -138,10 +139,10 @@ crates/
 ├── voltex_ai        — NavMesh(+builder), A*, Funnel, steering, obstacle avoidance
 ├── voltex_net       — UDP, NetServer/Client, Reliable/Ordered, Snapshot(delta), Interpolation
 ├── voltex_script    — Lua 5.4, LuaState, table interop, coroutine, sandbox, hot reload
-└── voltex_editor    — IMGUI, text_input, scroll, drag&drop, docking, UiRenderer
+└── voltex_editor    — IMGUI, text_input, scroll, drag&drop, docking, 3D viewport, UiRenderer
 ```
 
-## 테스트: 501개 전부 통과
+## 테스트: 510개 전부 통과
 
 - voltex_math: 37
 - voltex_platform: 3
@@ -153,7 +154,7 @@ crates/
 - voltex_ai: 24
 - voltex_net: 36
 - voltex_script: 18
-- voltex_editor: 38
+- voltex_editor: 47
 
 ## Examples (12개 + survivor_game)