release: 0.12.3 HostLink-first installation and companion wheels

[Xuwznln]

Changes

• Default Python/Conda/offline installation uses HostLink, without ROS.
• Keep only default, ros2 and full installation profiles; retire unilabos-env.
• Full includes documentation, tests, development tools and bundled Python driver dependencies; native ROS stays explicit.
• Distribute patched NumPy 2 Opentrons and pinned PLR as companion release wheels, never upload them to PyPI.
• Verify single-root installations, actual Opentrons labware and split Host/Slave demos; generate docs outside tracked source.
• Close full Conda dependencies (original PDF font packages, portable OPC-UA, Colcon notification); keep Windows GUI SDKs Windows-only.
• Initialize isolated Windows AppData in packaging tests without touching the real user profile or skipping font imports/pip check.

Validation

• Local regression: 750 passed, 5 skipped, including seven complete HostLink split-process demos.
• Latest installation/docs/release contracts: 79 passed plus 8 subtests.
• Fresh full Python installation: pip check, extras metadata and Opentrons 96-well creation passed.
• Full Windows Conda package: imports, font imports, pip check and all full dependency versions passed.
• Complete Sphinx HTML build with native ROS action definitions passed; existing documentation warnings remain.
• Four-platform wheelhouse build passed: https://github.com/deepmodeling/Uni-Lab-OS/actions/runs/35115060065
• Four-platform no-ROS Conda-Pack preflight passed: https://github.com/deepmodeling/Uni-Lab-OS/actions/runs/35112049037
• Runtime CI passed before the final packaging-test-only change: https://github.com/deepmodeling/Uni-Lab-OS/actions/runs/35111809025
• Latest CI rerun: https://github.com/deepmodeling/Uni-Lab-OS/actions/runs/35115060035
• Latest full Conda matrix: https://github.com/deepmodeling/Uni-Lab-OS/actions/runs/35115057562

Formal publication waits for the latest remote checks. Generated artifacts and unrelated worktree files are excluded. CI-only default-branch synchronization was merged separately in #322.