Fix NSIS installer abort when openXYOS livez is slow

[XYAIStudio]

Summary

Windows Setup of v0.0.1 aborted around 40% after extracting openXYOS:

1. extract-openxyos.cmd printed 系统找不到指定的批处理标签 - liveNodeOk and exited 1.
2. node\node.exe and nested openxyos\dist\index.html were already on disk; top-level dist\index.html is not required. FreeOS-openXYOS was created.
3. probeOpenXYOS then waited 60s for http://127.0.0.1:3780/api/health/livez and Aborted the whole install (exit 12 / error 68) before writing .install-ready. Port 3780 was not occupied — the old MessageBox was misleading.

Root cause: the generated cmd wrote liveNodeOk: but cmd.exe only accepts :liveNodeOk as a goto target.

This PR:

• Writes :liveNodeOk and ends extract with exit /b 0 when LIVE has node\node.exe plus dist\index.html or openxyos\dist\index.html.
• Softens the install-time livez probe: wait 90s, re-run the LIMITED FreeOS-openXYOS task once at 30s, then warn + continue (DetailPrint + information MessageBox). Does not blame a busy 3780 port.
• Writes .install-ready after layout + autostart, before the livez wait, so Organization can start the sidecar later even if livez is still down.
• Still Abort only when node/dist are missing (requireOpenXYOSLayout / error 67).
• Does not spawn Node as admin (IShellDispatch2 / medium IL unchanged).
• Adds a string-level test that the generated cmd contains :liveNodeOk and no liveNodeOk: label, and that .install-ready is stamped before probe.

Target branch

• Base is develop (feature / fix — default)
• Base is main (this repo ships installer fixes to main)

Type of change

• Bug fix
• New feature
• Breaking change
• Documentation
• Refactor / chore
• Release / hotfix

Test plan

• uv run pytest tests/unit/desktop/test_nsis_uninstall.py -q — 16 passed
• make lint + make typecheck — green
• make test — 3424 passed, 15 skipped (pre-stamp-move; NSIS tests re-run after)
• GitHub CI (Linux + Windows + desktop package)
• Added/updated tests (test_nsis_extract_cmd_uses_colon_prefixed_batch_labels; probe no longer Aborts / error 68; .install-ready before probe)

How to verify on Windows:

1. Build/install FreeOS-desktop-windows-amd64-*.exe elevated.
2. Extract log must not contain 系统找不到指定的批处理标签 and should show extract exit 0 once node.exe + nested or flat dist\index.html exist.
3. If livez is slow/down, Setup shows a warning and finishes. %LOCALAPPDATA%\FreeOS\openxyos\.install-ready, HKCU Run FreeOS-openXYOS, and the logon task remain even when port 3780 never answered.

Checklist

• Updated CHANGELOG.md (if user-facing)
• README / docs updated (if needed)