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>

Docs/Vault/.obsidian/core-plugins.json

@@ -0,0 +1,33 @@
+{
+  "file-explorer": true,
+  "global-search": true,
+  "switcher": true,
+  "graph": true,
+  "backlink": true,
+  "canvas": true,
+  "outgoing-link": true,
+  "tag-pane": true,
+  "footnotes": false,
+  "properties": true,
+  "page-preview": true,
+  "daily-notes": true,
+  "templates": true,
+  "note-composer": true,
+  "command-palette": true,
+  "slash-command": false,
+  "editor-status": true,
+  "bookmarks": true,
+  "markdown-importer": false,
+  "zk-prefixer": false,
+  "random-note": false,
+  "outline": true,
+  "word-count": true,
+  "slides": false,
+  "audio-recorder": false,
+  "workspaces": false,
+  "file-recovery": true,
+  "publish": false,
+  "sync": true,
+  "bases": true,
+  "webviewer": false
+}