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>

Assets/_Project/Materials/M_Dummy.mat

@@ -114,12 +114,12 @@ Material:
     - _GlossMapScale: 0
     - _Glossiness: 0
     - _GlossyReflections: 0
-    - _Metallic: 0
+    - _Metallic: 0.7
     - _OcclusionStrength: 1
     - _Parallax: 0.005
     - _QueueOffset: 0
     - _ReceiveShadows: 1
-    - _Smoothness: 0.5
+    - _Smoothness: 0.35
     - _SmoothnessTextureChannel: 0
     - _SpecularHighlights: 1
     - _SrcBlend: 1
@@ -129,8 +129,8 @@ Material:
     - _XRMotionVectorsPass: 1
     - _ZWrite: 1
     m_Colors:
-    - _BaseColor: {r: 1, g: 0.15, b: 0.15, a: 1}
-    - _Color: {r: 1, g: 0.14999998, b: 0.14999998, a: 1}
+    - _BaseColor: {r: 0.09, g: 0.1, b: 0.12, a: 1}
+    - _Color: {r: 0.089999996, g: 0.09999997, b: 0.11999995, a: 1}
     - _EmissionColor: {r: 0, g: 0, b: 0, a: 1}
     - _SpecColor: {r: 0.19999996, g: 0.19999996, b: 0.19999996, a: 1}
   m_BuildTextureStacks: []