TOUCH-SAFE SORT HEADER UPDATE (v96)
- The generated directory listing column headers "Name", "Last modified", and "Size" are now much larger touch targets.
- Deploy lambda-edge-directory-browser/index.mjs to Lambda@Edge and publish a new version to make the public directory pages show the larger headers.

START HERE — 8k.art S3 + CloudFront Directory Indexer
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This is the amnesia-safe deployment checklist.

GOAL
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Make https://8k.art/beta/ browseable like an Apache directory.
Let CloudFront cache directory pages and .directory-index.json for 365 days.
When S3 changes, the updater Lambda rebuilds the index and invalidates CloudFront.

FILES AND WHERE THEY GO
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1. s3-directory-index-updater/index.mjs
   Goes to: normal AWS Lambda triggered by S3 ObjectCreated/ObjectRemoved events.
   Purpose: rebuild .directory-index.json and invalidate CloudFront.

2. s3-directory-index-updater/package.json
   Goes with the updater Lambda deployment package.
   Purpose: dependencies @aws-sdk/client-s3 and @aws-sdk/client-cloudfront.

3. lambda-edge-directory-browser/index.mjs
   Goes to: Lambda@Edge in us-east-1, CloudFront Origin request association.
   Purpose: render public folder pages like https://8k.art/beta/.

4. cloudfront-function-headers/allow-all-cors-and-inline-text.js
   Goes to: CloudFront Function, usually Viewer response.
   Purpose: CORS and inline text/source display headers.

5. Documentation/source files in this package
   Go to: s3://www.8k.art/beta/s3-cloudfront-indexer/
   Purpose: public documentation and source package.

REQUIRED UPDATER LAMBDA ENVIRONMENT VARIABLE
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CLOUDFRONT_DISTRIBUTION_ID=YOUR_8K_ART_DISTRIBUTION_ID

Recommended explicit values:
ENABLE_CLOUDFRONT_INVALIDATION=true
DIRECTORY_INDEX_CACHE_CONTROL=public, max-age=31536000, s-maxage=31536000, immutable
UPDATE_BUCKET_ROOT_INDEX=false

REQUIRED IAM PERMISSION
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The updater Lambda role needs cloudfront:CreateInvalidation.
Use policies/s3-directory-index-updater-policy-example.json and replace YOUR_BUCKET_NAME with www.8k.art.

DEPLOYMENT ORDER
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1. Upload this package to s3://www.8k.art/beta/s3-cloudfront-indexer/ for public docs.
2. Deploy s3-directory-index-updater/index.mjs to the S3 event updater Lambda.
3. Set CLOUDFRONT_DISTRIBUTION_ID on that updater Lambda.
4. Verify updater Lambda has S3 trigger for ObjectCreated and ObjectRemoved.
5. Deploy lambda-edge-directory-browser/index.mjs to Lambda@Edge in us-east-1.
6. Publish a numbered Lambda@Edge version.
7. Attach that numbered version to CloudFront as Origin request for the beta behavior.
8. Deploy cloudfront-function-headers/allow-all-cors-and-inline-text.js as CloudFront Function if needed.
9. Test upload, overwrite, delete in s3://www.8k.art/beta/.
10. Confirm https://8k.art/beta/ updates after invalidation.

DO NOT DO THESE THINGS
----------------------
- Do not delete the CloudFront distribution.
- Do not delete old Lambda versions before testing.
- Do not attach $LATEST to Lambda@Edge. Use a numbered version.
- Do not remove the updater Lambda S3 event trigger.
- Do not depend on short cache TTLs. The intended model is 365-day cache plus invalidation.

TEST
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Upload: beta/test-cache-invalidation.txt
Refresh: https://8k.art/beta/
Overwrite the file.
Refresh the file URL through CloudFront.
Delete the file.
Refresh https://8k.art/beta/

SUCCESS
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If folder listings and changed files update after S3 changes, while unchanged content can cache for a year, the system is working.