v0.6.0 - Open-Source Release

What's Changed

Open-source release. This version prepares the repository for its public
home: proper licensing, a support disclaimer, cleaned-up docs, and the
removal of the last dead code left over from the pre-0.4.0 in-process
matching engine.

Added

• Apache License 2.0. A root LICENSE file, Physna SPDX headers on
  every source file, and the license shipped inside the release zip.
• Support disclaimer (docs/DISCLAIMER.md, also shown on the
  extension's documentation pages and summarized in the README): the
  project is open source and maintained best-effort — large issues and
  failures are prioritized; minor issues and feature requests may not
  receive a timely response. The hosted Physna platform remains a separate
  commercial service.

Changed

• Default environment is now Production (app-api.physna.com) instead
  of the internal dev stack; a fresh install's Environment dropdown starts
  on "Production (app)" with the matching token endpoint pre-filled.
• Developer docs (docs/DEVELOPING.md, AGENTS.md) now use generic
  Python-environment instructions instead of machine-specific paths.

Removed

• PointCloudConverter — dead code from the in-process matching era
  (USD/STL→NPZ export, Open3D mesh reconstruction); nothing called it. CAD
  parts still convert to USD for placement via MeshConverter.
• The NVIDIA-proprietary Kit-template license headers (replaced by the
  Apache-2.0 headers above).
• The internal API guide (docs/API-Guide-ScanSearch.md) — it carried
  internal stack URLs and a tenant ID and had drifted out of date; the
  workflow summary lives in docs/Overview.md.
• Stale editor/tooling config: tracked .vscode/ files (already
  gitignored) and an unused renovate.json.