ts-node 10.x is incompatible with the TypeScript 7 compiler API (cdk synth
fails with "Cannot read properties of undefined (reading 'fileExists')").
Swap the cdk.json app runner from ts-node to tsx, drop ts-node, pin tsx to
4.23.0 (matching sh-mcp), and bump typescript to ~7.0.2. Verified via
cdk synth (exit 0) and tsc build.
SAM is for simple serverless stacks; this project has ECS, VPC, and
multi-service composition which requires CDK. Migration brings
ContainerImage.fromAsset() for automatic Docker builds on deploy,
matching the seahaven-slack-bot pattern.
Also fixes: Bedrock model ID (add version suffix), Gmail history API
parameter (labelId not labelIds), classify JSON extraction (handle
markdown fences), and digest block limit (cap sections at 5 items
to stay under Slack's 50-block limit).
