v0.6.0

Windows packaging overhaul (Go + .NET agents). Both Windows packages now ship
a single binary with agent.cfg in the same folder as the executable, and both
run as a real Windows Service.

✨ New Features

• feat(windows): the Go agent now installs a Windows Service (go-glpi-agent,
  auto start, LocalSystem, runs the daemon loop with restart-on-failure) instead
  of an hourly Scheduled Task. The MSI, install.ps1 and uninstall.ps1 manage
  the service; upgrades from ≤ 0.5.x remove the legacy Scheduled Task.

🔧 Improvements

• feat(windows): agent.cfg now lives next to the binary for both agents
  (C:\Program Files\go-glpi-agent\agent.cfg and
  C:\Program Files\DotnetGlpiAgent\agent.cfg); state and logs remain under
  C:\ProgramData. Existing configs are preserved on upgrade; PURGE=1 removes
  them.
• feat(dotnet): the .NET MSI and portable zip now ship a single self-contained
  executable (PublishSingleFile) instead of the multi-DLL publish layout.
• ci(dotnet): drop the "Schema fixtures present" gate that asserted gitignored,
  lab-generated files and made every CI run fail; assert the single-binary
  publish output instead.

Full Changelog: v0.5.1...v0.6.0