docs-site: Pi host has zero presence on the published site (6 gaps)

[SUaDtL]

Branch: feat/pi-support · Tribunal run 2026-07-17-pi-support-branch · Finding: findings/docs-pi/01-06
No Pi page, sidebar entry, install/trust/version/Windows/uninstall/troubleshooting content on the site; all lives in repo-root README/docs only. 3 high / 3 medium gap files enumerate the pages to add.

[SUaDtL]

Verified against PR #313 head 9ed248f4: the site now has a sidebar-linked getting-started/pi.md page covering Git-only installation, project trust, activation, doctor verification, supported versions, upgrade/removal links, and promoted Windows behavior. Compatibility, enforcement, uninstalling, and troubleshooting pages carry the corresponding Pi-specific guidance. Hosted site generation and build checks are green. All six documented gaps are implemented on #313, which now carries Closes #330.