Normalize materials, add Unity.UI, cleanup scene

Unify and sanitize material YAML, update asmdef references, add Fusion .idea config, and trim scene serialization noise.

- Materials: replaced shader fileIDs/guid with neutral reference, added _GLOSSYREFLECTIONS_OFF keyword and common properties (_Mode, _UVSec), cleared stringTagMap, adjusted blend/ZWrite values for transparent materials to match intended settings.
- asmdef: added "Unity.UI" to both Fusion.Editor and Fusion.Runtime assembly references.
- Added IDE config files for Assets/Photon/Fusion/Runtime/Statistics (.gitignore, encodings.xml, indexLayout.xml, inspection profile, vcs.xml).
- Plugins: updated GUIDs in Sirenix/Odin Inspector Unity.Mathematics meta files.
- Scene: removed several redundant/unneeded serialized fields (Universal RP camera/light/volume extras and empty player list) to reduce clutter.

These changes aim to fix shader reference inconsistencies, align material settings, ensure Unity.UI dependency is declared, and reduce noisy serialized data in the scene.

Assets/Plugins/Sirenix/Odin Inspector/Modules/Unity.Mathematics.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: 049b3685a0978b3458f7d3cb39e093a5
+guid: f00f776f1a5a52b4ba23e334684f1879
 folderAsset: yes
 DefaultImporter:
   externalObjects: {}

Assets/Plugins/Sirenix/Odin Inspector/Modules/Unity.Mathematics/manifest.txt.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: d709a8c107bc33340b1dfbb0cdb4a9c8
+guid: 1257a8bc09cd4794e85fc95cebfccb2b
 TextScriptImporter:
   externalObjects: {}
   userData: