handleInstallScript and handleUpdateScript are registered on the bare
gin engine at /install and /update, outside the /api group the
generated document's BasePath assumes. Their @Router annotations
therefore published /api/install and /api/update, paths that 404 —
the reference page told a reader to curl a URL that does not exist.
Removed the swag annotations from both handlers (replaced with a plain
comment explaining why) rather than adding a corrected @Router, since
swag has no per-route BasePath override and there is nothing lost by
leaving two shell-script endpoints out of a JSON API reference — their
.ps1 counterparts were already undocumented for the same reason.
Regenerated internal/api/docs/openapi.json accordingly.