Set up DOTS + Netcode for Entities foundation

One-time stack setup per Docs/dots-setup-task.md (Unity 6.4.7 / 6000.4.7f1).
Packages: entities 6.4.0, entities.graphics 6.4.0, netcode 1.13.2, physics 1.4.6.

- Assets/_Project asmdef split: ProjectM.Simulation/Client/Server/Authoring (root ns ProjectM)
- GameBootstrap : ClientServerBootstrap; verified separate client + server worlds in Play Mode
- Gameplay subscene wired into SampleScene as a baking target
- Heartbeat component + Burst ISystem; EditMode smoke test green (1/1)
- In-repo Obsidian vault (Docs/Vault) incl. DR-001 (plain-Entities test over internal NetCodeTestWorld)
- Portable .mcp.json (basic-memory + serena via ${CLAUDE_PROJECT_DIR}); CLAUDE.md conventions
- .gitignore for DOTS baking cache + machine-local config

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

Packages/manifest.json

@@ -1,15 +1,23 @@
 {
   "dependencies": {
+    "com.coplaydev.unity-mcp": "https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity#main",
     "com.unity.ai.navigation": "2.0.12",
+    "com.unity.cinemachine": "3.1.6",
     "com.unity.collab-proxy": "2.12.4",
+    "com.unity.entities": "6.4.0",
+    "com.unity.entities.graphics": "6.4.0",
     "com.unity.ide.rider": "3.0.40",
     "com.unity.ide.visualstudio": "2.0.27",
     "com.unity.inputsystem": "1.19.0",
     "com.unity.multiplayer.center": "1.0.1",
+    "com.unity.netcode": "1.13.2",
+    "com.unity.physics": "1.4.6",
+    "com.unity.probuilder": "6.0.9",
     "com.unity.render-pipelines.universal": "17.4.0",
     "com.unity.test-framework": "1.6.0",
     "com.unity.timeline": "1.8.12",
     "com.unity.ugui": "2.0.0",
+    "com.unity.visualeffectgraph": "17.4.0",
     "com.unity.visualscripting": "1.9.11",
     "com.unity.modules.accessibility": "1.0.0",
     "com.unity.modules.adaptiveperformance": "1.0.0",