[callumalpass]

Change

• Install the existing sdk-dev-eaa4e697-staging.tgz only in the staging Pages build path.
• Restore package.json and pnpm-lock.yaml after the build, including failures.
• Leave the production SDK pin, production web/iOS paths, native intake, and legacy-pages untouched.

Validation

• rpnpm test, test:release, format:check, typecheck, lint, test:conformance: all pass.
• Staging assets built with rpnpm and pulled for local preview.
• Existing headless repro adapted only to route staging-origin requests to local preview: sign-in renders; no startup error.

Main merge intentionally triggers staging Pages deployment; no production/native publishing dispatch or release tag.