Implements the AWS Comprehend PII redaction utility requested in #290 for the JavaScript SDK.

/claim #290

What changed

• Added AwsComprehendRedactor under the AI package.
• Uses Amazon Comprehend DetectPiiEntities to detect PII spans.
• Redacts prompts using stable AWS offsets, including Unicode-safe code point offset conversion for JavaScript strings.
• Supports filtering by entity type and confidence score.
• Adds helpers for prompt strings and chat message arrays.
• Exports the redactor from @arakoodev/edgechains.js/ai.
• Adds mocked unit tests for offset redaction, filtering, chat message handling and emoji/code-point offsets.
• Adds a working example under examples/aws-comprehend-redaction.

Verification

npx jest src/ai/src/tests/awsComprehendRedactor.test.ts --runInBand
npx tsc -p tsconfig.json --noEmit
npx tsc -b

Results locally:

• awsComprehendRedactor.test.ts: 6 tests passed.
• tsc --noEmit: passed.
• tsc -b: passed.
• GitHub Actions js: passed.
• GitHub Actions CLAAssistant: passed.
• npm run build: not run successfully on Windows because the existing script uses Unix rm -rf.

Note

The real AWS call requires AWS credentials and region configured in the environment. Tests mock the Comprehend client so CI does not need AWS credentials.