Upgrade: Unity 6.4.7 -> 6.5.0 (DOTS stack onto unified 6.5)

Editor 6000.4.7f1 -> 6000.5.0f1. DOTS packages leave their independent
1.x/2.x lines for unified 6.5.0 versioning: netcode 1.13.2 -> 6.5.0,
physics 1.4.6 -> 6.5.0, transport 2.7.2 -> 6.5.0, entities/collections/
graphics 6.4.0 -> 6.5.0, mathematics 1.3.3 -> 1.4.0 (burst stays 1.8.29).
URP/ShaderGraph/VFX 17.4 -> 17.5, ugui 2.0 -> 2.5, test-framework 1.6 -> 1.7.
charactercontroller 1.4.2 + local rukhanka 2.9.0 unchanged (resolve on 6.5
via SemVer floor). Includes the URP global-settings + VFX/MPPM/package-manager
ProjectSettings migrations 6.5 wrote on first open.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ProjectSettings/VFXManager.asset

@@ -15,7 +15,6 @@ VFXManager:
   m_MaxScrubTime: 30
   m_MaxCapacity: 100000000
   m_CompiledVersion: 7
-  m_RuntimeVersion: 39
+  m_RuntimeVersion: 40
   m_RuntimeResources: {fileID: 11400000, guid: bc10b42afe3813544bffd38ae2cd893d, type: 2}
-  m_EditorResources: {fileID: 11400000, guid: 64142473281487e4da1e5eb23da2ab2d, type: 2}
   m_BatchEmptyLifetime: 300