Serverless deploy to LocalStack fails: “Invalid character in header content [authorization]”

まだ誰も着手していません。

Running serverless deploy --stage local against LocalStack aborts during the “Resolving AWS account ID” step with the error:
```bash
Unable to find function cleanup on plugin Esbuild
Deploying "sls" to stage "local" (us-east-1)
Using serverless-localstack
Using serverless-localstack
serverless-localstack: Reconfigured endpoints

Error: Failed to resolve AWS account ID: Invalid character in header content ["authorization"]
```
deployment never reaches packaging or CloudFormation synthesis

serverless.ts
```typescript
plugins: ['serverless-iam-roles-per-function', 'serverless-localstack'],

custom:
localstack:
stages: ['local']
edgePort: 4566
host: 'http://localhost'

provider:
name: aws
runtime: nodejs22.x
environment:
AWS_ENDPOINT_URL: 'http://localhost:4566'
AWS_ACCESS_KEY_ID: '000000000001'
AWS_ACCOUNT_ID: '000000000001'
```

docker-compose.yml
```yml
s3mock:
image: adobe/s3mock:latest
environment:
- retainFilesOnExit=true
- root=root
ports:
- 9090:9090
volumes:
- ./uploadedFiles:/root

localstack:
container_name: localstack
image: localstack/localstack
ports:
- 4566:4566
- 4510-4559:4510-4559
environment:
- DEBUG=${DEBUG:-0}
- SERVICES=lambda,sqs,sns
volumes:
- '${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack'
- '/var/run/docker.sock:/var/run/docker.sock'
```

**Versions**
| Component | Version |
|--------------------------|-------------------------------------------------------|
| Serverless Framework | 4.14.3 |
| serverless-localstack | 1.3.1 |
| LocalStack Docker image | `localstack/localstack:latest` (pulled 2025-05-14) |
| Node.js | 22.0.0 |

`serverless.ts` と `docker-compose.yml` を使って `serverless deploy --stage local` を再現し、「Resolving AWS account ID」ステップと authorization-header エラーに焦点を当てます。記載されている Serverless Framework、serverless-localstack、LocalStack、Node.js のバージョンを確認してください。アカウント解決を越えて packaging と CloudFormation の合成までデプロイが進み、invalid-header の失敗が発生しなければ完了です。

索引モデルが issue の本文から書いたものです。