"## Deploy" led with deploy.ps1 and mentioned the installer only
afterwards, which is backwards now that the installer is released.
- Deploy leads with the installer, with the by-hand overlay copy
(INSTALL.md Appendix A2) as the supported alternative.
- deploy.ps1 gets its own subsection as the developer path: it deploys
from a working tree, which is the one thing the installer cannot do,
and it installs no sidecar and checks no protocol pairing.
- CONTRIBUTING: note that changes reach shards through a release, so a
change that only works when deploy.ps1 copies it does not ship.
Co-Authored-By: Claude <noreply@anthropic.com>
