feat: add PNG decoder, query3/4, Capsule+GJK/EPA, friction, Lua engine API

- PNG decoder with self-contained Deflate decompressor (RGB/RGBA)
- ECS query3 and query4 for multi-component queries
- Capsule collider + GJK/EPA narrow phase for convex shapes
- Coulomb friction in physics solver
- Lua engine API bindings (spawn, position, entity_count)

Tests: 255 → 286 (+31)

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

.claude/settings.local.json

@@ -47,7 +47,9 @@
       "Read(//c/tmp/**)",
       "Bash(tar xzf:*)",
       "Bash(cp lua-5.4.7/src/*.c lua-5.4.7/src/*.h C:/Users/SSAFY/Desktop/projects/voltex/crates/voltex_script/lua/)",
-      "Bash(cd:*)"
+      "Bash(cd:*)",
+      "Bash(git status:*)",
+      "Bash(git push:*)"
     ]
   }
 }

Cargo.lock

@@ -2152,6 +2152,8 @@ name = "voltex_script"
 version = "0.1.0"
 dependencies = [
  "cc",
+ "voltex_ecs",
+ "voltex_math",
 ]
 
 [[package]]

docs/superpowers/specs/2026-03-25-png-decoder.md

@@ -0,0 +1,33 @@
+# PNG Decoder — Design Spec
+
+## Overview
+
+voltex_renderer에 PNG 디코더를 추가한다. Deflate(Huffman+LZ77) 자체 구현으로 외부 의존 없이 PNG 파일을 파싱.
+
+## Scope
+
+- PNG 시그니처 + 청크 파싱 (IHDR, IDAT, IEND)
+- 8-bit RGB (color_type=2), 8-bit RGBA (color_type=6)
+- Deflate 디코더 (zlib wrapper + fixed/dynamic Huffman + LZ77)
+- PNG 필터 복원 (None, Sub, Up, Average, Paeth)
+
+## Out of Scope
+
+- 인터레이스 (Adam7)
+- 16-bit depth
+- 팔레트 (color_type=3)
+- 그레이스케일 (color_type=0, 4)
+- Adler32 검증
+
+## Files
+
+- `crates/voltex_renderer/src/deflate.rs` — inflate (Create)
+- `crates/voltex_renderer/src/png.rs` — parse_png (Create)
+- `crates/voltex_renderer/src/lib.rs` — 모듈 등록 (Modify)
+
+## Test Plan
+
+- deflate: inflate fixed Huffman compressed data
+- png filters: each filter type reconstruction
+- parse_png: manually crafted 2x2 PNG roundtrip
+- RGB→RGBA conversion