v0.3.2 — drop mcp env substitutions

[0.3.2] - 2026-04-15

Fixed

• Plugin manifest: removed env: { X: "${user_config.X}" } from the
  MCP server blocks. The installer validated any substituted value
  as required regardless of default, so leaving optional tokens
  blank failed plugin load with "Missing required user configuration
  value." The MCP servers already read these from os.environ with
  graceful fallback (or from .vr-state/vr-config.json via
  bin/vr-backend.sh), so the env injection was dead weight.