Apple review requires a test account login path that doesn't depend on
Google OAuth. Add amazon-cognito-identity-js for direct SRP auth with a
native email/password form on the login screen. Fill in the empty Cognito
client ID and pool ID, fix the Cognito domain prefix, and align CDK
callback URLs with the app's actual URL scheme. Enable push-triggered
mobile deploys, add CDK outputs for client IDs, fix stale README
references, and add mobile/README.md.
The log group already exists — created by the compute stack's
logRetention setting on the suggestions Lambda. Adding it to the
foundation stack caused a duplicate resource error on deploy.
oss-index-creator Lambda was missing functionName, arm64 architecture,
and explicit log retention — all required by the engineering handbook.
CI workflow was not passing node-version to reusable workflows, risking
drift. Removed unused _api_request helper from all four main Lambdas.
Added missing suggestions log group to foundation stack.
