ADR-0059: repurpose waterdeep from Ray worker to local AI agent

Replace the proposed Ray cluster worker role with a dedicated local
AI agent for BlenderMCP 3D avatar creation (supporting ADR-0062).

waterdeep's Metal GPU provides hardware-accelerated rendering in
Blender — far superior to Kasm's CPU-only DinD environment. The
Ray cluster GPU fleet is fully allocated and stable; adding MPS
complexity is not justified.

Also adds cross-reference from ADR-0062 to ADR-0059.

decisions/0062-blender-mcp-3d-avatar-workflow.md

@@ -437,6 +437,7 @@ VRM files are immutable once promoted — updated models get a new filename (e.g
 * Related to [ADR-0026](0026-storage-strategy.md) (storage strategy — gravenhollow NFS-fast, Quobyte S3, rclone)
 * Related to [ADR-0044](0044-dns-and-external-access.md) (DNS and external access — Cloudflare Tunnel, split-horizon)
 * Related to [ADR-0049](0049-self-hosted-productivity-suite.md) (Kasm Workspaces)
+* Related to [ADR-0059](0059-mac-mini-ray-worker.md) (waterdeep as local AI agent — primary 3D creation workstation with Metal GPU)
 * [BlenderMCP GitHub](https://github.com/ahujasid/blender-mcp)
 * [VRM Add-on for Blender](https://vrm-addon-for-blender.info/en/)
 * [VRM Specification](https://vrm.dev/en/)