mlx-workbench v0.2.0

Added

• Web UI modularization: DOM helpers (dom.js), API envelope unwrapping
  (envelope.js), payload assembly (payloads.js), and duplicate-group
  splitting (duplicates.js) extracted from app.js following the existing
  module pattern, with behavioral tests. Static JS tests now run as part of
  make test (new test-js target).
• View presentation tests: HomeNextAction derivation ladder (Home tab's
  next safe action).
• Serve converted outputs outside the Hugging Face cache: the agent's
  serve start --path flows through the workbench bridge, web route
  (/api/serve/preview|start accept exactly one of repo/path), and the
  SwiftUI app (WorkbenchAPI picks --repo vs --path; serve-status
  comparisons normalize through ServerInfo.modelIdentity). Requires the
  pinned mlx-agent with local-path serve support.