New pattern submission - apigw-http-api-lambda-bedrock-dynamodb-vector-search-cdk

## Pattern

`apigw-http-api-lambda-bedrock-dynamodb-vector-search-cdk`

A TypeScript AWS CDK pattern that creates a serverless semantic-search API with Amazon API Gateway HTTP API, AWS Lambda, Amazon Bedrock embeddings, and a native Amazon DynamoDB vector index.

## Why this pattern is useful

This pattern gives developers a reusable starting point for semantic search while keeping vectors and operational data together in DynamoDB. It avoids a separate vector database and record-synchronization pipeline, uses a tenant-scoped composite primary key so document IDs cannot collide across tenants, demonstrates tenant-scoped searches with optional category filtering, and provides an idempotent custom resource for the DynamoDB vector-index lifecycle while native CDK and CloudFormation coverage is unavailable.

The focused integration can be adapted for document discovery, product catalogs, support search, multi-tenant SaaS, and knowledge-search APIs. The collection currently has an S3 Vectors RAG example but no native DynamoDB vector-search pattern implemented with AWS CDK and TypeScript.

## Scope

- **AWS services:** Amazon API Gateway, AWS Lambda, Amazon Bedrock, and Amazon DynamoDB
- **Infrastructure as code:** AWS CDK
- **Language:** TypeScript
- **Custom code:** One application Lambda handler and the bounded custom-resource provider required to manage the vector index
- **Pattern type:** Focused IaC integration, not a complete application, utility, or demo repository
- **PR scope:** One pattern directory only

## Model compliance

- [`example-pattern.json`](https://github.com/proton0210/serverless-patterns/blob/proton0210-feature-dynamodb-vector-search-cdk/apigw-http-api-lambda-bedrock-dynamodb-vector-search-cdk/example-pattern.json) contains the complete **354-word** introduction.
- It contains **4** AWS documentation and blog resources.
- The author entry contains a one-sentence bio plus LinkedIn and Twitter IDs.
- The README includes Requirements, Architecture, Flow, Resources, How it works, Deployment Instructions, Testing, and Cleanup.
- The architecture diagram uses official AWS Architecture Icons.

## Validation

- A clean Node.js 24 dependency installation, TypeScript build, all **9 tests across 3 suites**, CDK synthesis, and repository metadata schema validation passed.
- The exact submitted commit, [`cf375c1`](https://github.com/proton0210/serverless-patterns/commit/cf375c1adc3f2a81e9a330163604bdf5bbc92602), was deployed by following the README from a clean application-stack state and reached `CREATE_COMPLETE`.
- Both documented interfaces passed: API Gateway HTTP requests and direct Lambda invocations. Live testing also covered tenant isolation, category filtering, malformed JSON, oversized embedding input, oversized multibyte tenant keys, and an unknown route.
- Application, custom-resource provider, and framework logs contained no unexpected errors.
- The documented cleanup reached `DELETE_COMPLETE`; follow-up checks found no residual application stack, DynamoDB tables, Lambda functions, HTTP APIs, IAM roles, or application log groups.
- No credentials, account identifiers, API endpoints, profiles, role ARNs, or generated deployment files are included in the PR.

## GitHub PR for template

https://github.com/aws-samples/serverless-patterns/pull/3275

Start by reviewing the pattern directory named apigw-http-api-lambda-bedrock-dynamodb-vector-search-cdk and the linked template PR #3275, then compare its example-pattern.json and README with the repository’s pattern conventions. Run the stated TypeScript build, test suites, CDK synthesis, and metadata validation; done means the pattern meets those checks and its documented deployment and cleanup complete successfully.

Written by the indexing model from the issue text.