Move PO lambdas under lambdas/po/, add WO pipeline under lambdas/wo/.
Two independent CloudFormation stacks in one CDK app. Fix WO stack
compliance: ARM64 architecture, 60-day log retention, aarch64 bundling,
RETAIN on Anthropic secret. Remove stale CodePipeline buildspec.
CDK stack with SES receipt rule, S3 bucket, email processor Lambda
(Claude-powered extraction), web UI Lambda with Function URL, and
DynamoDB for storage. Includes reprocessing script for missed emails.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>