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/06_Roadmap/Milestones.md

@@ -0,0 +1,16 @@
+---
+tags:
+- roadmap
+- milestones
+updated: 2026-05-29
+permalink: gamevault/06-roadmap/milestones
+---
+
+# Milestones
+
+| Milestone | Goal | Status |
+|---|---|---|
+| **M0 — Foundation** | DOTS + Netcode stack, asmdef split, bootstrap, smoke test green | ✅ Done 2026-05-29 — [[2026-05-29_Project_Setup]] |
+| **M1 — _TBD_** | Define the first playable slice (core loop + first predicted ghost) | ⬜ |
+
+Promote items from [[Backlog]] here when committed.