Import art/VFX asset packs + game-feel systems; normalize texture extensions to lowercase for LFS

Add BefourStudios SciFi environment packs, Gabriel Aguiar VFX, and the
ShaderCrew Toon Shader embedded packages, plus combat/enemy/wave/death
gameplay systems and supporting vault docs/screenshots.

Rename 11 vendor textures from uppercase .PNG/.HDR to lowercase so the
case-sensitive Git LFS filters (*.png/*.hdr) match on case-sensitive
filesystems (Linux CI, case-sensitive macOS), not just locally where
core.ignorecase=true masks the gap. Each .meta moved with its asset so
GUID references are preserved. All ~1000 binaries tracked via LFS.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Packages/com.shadercrew.the-toon-shader.3d/Scripts/Shaders/STS~/URP/2020/TheToonShader_WithOutline_WithSTS_URP2020.shader.meta

@@ -0,0 +1,17 @@
+fileFormatVersion: 2
+guid: 488c8ac92b1e0cd4185509b7aa3575f7
+ShaderImporter:
+  externalObjects: {}
+  defaultTextures: []
+  nonModifiableTextures: []
+  preprocessorOverride: 0
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
+AssetOrigin:
+  serializedVersion: 1
+  productId: 269238
+  packageName: The Toon Shader
+  packageVersion: 1.4.2
+  assetPath: Packages/com.shadercrew.the-toon-shader.3d/Scripts/Shaders/STS/URP/2020/TheToonShader_WithOutline_WithSTS_URP2020.shader
+  uploadId: 919972

Packages/com.shadercrew.the-toon-shader.3d/Scripts/Shaders/STS~/URP/2020/TheToonShader_WithSTS_URP2020.shader.meta

@@ -0,0 +1,17 @@
+fileFormatVersion: 2
+guid: e885b2982824444479ff0104053bc193
+ShaderImporter:
+  externalObjects: {}
+  defaultTextures: []
+  nonModifiableTextures: []
+  preprocessorOverride: 0
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
+AssetOrigin:
+  serializedVersion: 1
+  productId: 269238
+  packageName: The Toon Shader
+  packageVersion: 1.4.2
+  assetPath: Packages/com.shadercrew.the-toon-shader.3d/Scripts/Shaders/STS/URP/2020/TheToonShader_WithSTS_URP2020.shader
+  uploadId: 919972