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/packages-lock.json

@@ -18,6 +18,20 @@
         "com.unity.entities.graphics": "1.4.16"
       }
     },
+    "com.shadercrew.the-toon-shader.3d": {
+      "version": "file:com.shadercrew.the-toon-shader.3d",
+      "depth": 0,
+      "source": "embedded",
+      "dependencies": {
+        "com.shadercrew.the-toon-shader.core": "1.4.2"
+      }
+    },
+    "com.shadercrew.the-toon-shader.core": {
+      "version": "file:com.shadercrew.the-toon-shader.core",
+      "depth": 0,
+      "source": "embedded",
+      "dependencies": {}
+    },
     "com.unity.ai.navigation": {
       "version": "2.0.12",
       "depth": 0,
@@ -283,7 +297,7 @@
     },
     "com.unity.searcher": {
       "version": "4.9.4",
-      "depth": 2,
+      "depth": 1,
       "source": "registry",
       "dependencies": {},
       "url": "https://packages.unity.com"
@@ -388,7 +402,7 @@
     },
     "com.unity.shadergraph": {
       "version": "17.4.0",
-      "depth": 1,
+      "depth": 0,
       "source": "builtin",
       "dependencies": {
         "com.unity.render-pipelines.core": "17.4.0",