fix(create-blocks-app): add CDK CLI to templates

[ikenyal]

Problem

Generated templates invoke cdk through their deploy and sandbox scripts but declare only aws-cdk-lib. On a fresh project, npx cdk therefore fetches a CLI on first use, adding latency and allowing the CLI version to float independently of the repository-supported toolchain.

Issue #, if available: #228

Changes

• Pin aws-cdk to 2.1122.0 in all seven standalone templates. This is the CLI version resolved by the repository lockfile and verified by the repository toolchain.
• Keep the CLI version independent from the aws-cdk-lib number: CDK Toolkit and Construct Library use separate versioning, and the Toolkit is backward compatible with supported library releases.
• Add a regression test that verifies each template pins the CLI version resolved in the repository lockfile.
• Add a patch changeset for @aws-blocks/create-blocks-app.

Validation

• npm run build --workspace @aws-blocks/create-blocks-app
• npm test --workspace @aws-blocks/create-blocks-app (51 passing tests)
• ./node_modules/.bin/cdk --version (2.1122.0)
• npm run lint:deps
• changeset status --since=origin/main

Checklist

• PR description included
• Tests are changed or added
• Relevant documentation is changed or added (not applicable: the existing scripts are unchanged; their required CLI is now installed with the template)

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[changeset-bot]

🦋 Changeset detected

Latest commit: 72b2e99

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@aws-blocks/create-blocks-app	Patch

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