feat(ecs): add hookDetails support for deployment lifecycle hooks

[rgoltz]

Issue # (if applicable)

N/A

Reason for this change

The AWS::ECS::Service CloudFormation resource supports a HookDetails field on DeploymentConfiguration.LifecycleHooks, but the CDK L2 construct does not expose it. This field allows passing custom parameters (as a JSON object) to lifecycle hook targets (e.g. Lambda functions) during ECS deployments.

Description of changes

• Added hookDetails property (Record<string, unknown>) to DeploymentLifecycleLambdaTargetProps
• Added hookDetails (string) to the internal DeploymentLifecycleHookTargetConfig interface
• Serialization via Fn.toJsonString to correctly handle CDK tokens at synth time
• Input validation ensuring only plain JSON objects are accepted (no arrays, primitives, or null)
• Passed the serialized value through DeploymentLifecycleHookTargetConfig into base-service.ts

Note: When hookDetails contains CDK tokens (e.g. cdk.Aws.STACK_NAME), the synthesized template will use Fn::ToJsonString, which requires the AWS::LanguageExtensions transform. CDK adds this transform automatically.

Describe any new or updated permissions being added

None.

Description of how you validated changes

• 6 new unit tests covering: happy path (nested objects), absence when undefined, CDK token resolution, rejection of arrays, primitives, and null
• Updated existing integration test (integ.blue-green-deployment-strategy) to include hookDetails
• Integration test deployed successfully with hook invocation confirmed
• Updated README example

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

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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

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
This security report is NOT a review blocker. Please try merge from main to avoid findings unrelated to the PR.
To suppress a specific rule, see Suppressing Rules.

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	Tests	Passed ☑️	Skipped	Failed ❌️
Security Guardian Results	24 ran	23 passed		1 failed

Test	Result
Security Guardian Results
packages/@aws-cdk-testing/framework-integ/test/aws-ecs/test/base/integ.blue-green-deployment-strategy.js.snapshot/aws-ecs-blue-green-deployment.template.json
ec2-no-open-security-groups.guard	❌ failure

• View Security Guardian Results

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
This security report is NOT a review blocker. Please try merge from main to avoid findings unrelated to the PR.
To suppress a specific rule, see Suppressing Rules.

---

	Tests	Passed ☑️	Skipped	Failed ❌️
Security Guardian Results with resolved templates	24 ran	23 passed		1 failed

Test	Result
Security Guardian Results with resolved templates
packages/@aws-cdk-testing/framework-integ/test/aws-ecs/test/base/integ.blue-green-deployment-strategy.js.snapshot/aws-ecs-blue-green-deployment.template.json
ec2-no-open-security-groups.guard	❌ failure

• View Security Guardian Results with resolved templates