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/Backlog.md

@@ -0,0 +1,16 @@
+---
+tags:
+- roadmap
+- backlog
+updated: 2026-05-29
+permalink: gamevault/06-roadmap/backlog
+---
+
+# Backlog
+
+Unordered pool of candidate work. Promote to a [[Milestones|milestone]] when committed.
+
+- [ ] Decide whether to upgrade Unity 6.4 → 6.6 for newer Entities (6.6.x). Stack is forward-compatible; `NetCodeTestWorld` stays internal regardless — see [[DR-001_Netcode_Test_Harness]].
+- [ ] Define the core gameplay loop and the first predicted player ghost.
+- [ ] Replace template `SampleScene` with a dedicated bootstrap scene + gameplay subscene.
+- [ ] Optional template cleanup: remove `com.unity.visualscripting`, `Assets/TutorialInfo/`, `Assets/Readme.asset` (delete each asset **with** its `.meta`).

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.