Optional DynamoDB mirror

Flag: enable_dynamodb = true in terraform.tfvars

Because S3 Annotations have no server-side query, DynamoDB is an optional read index — not a replacement for canonical metadata on the object.

	S3 Annotations (default)	+ DynamoDB
Source of truth	S3	S3
API read	Parallel GetObjectAnnotation	Table scan + filter
Best for	Demo scale (tens–hundreds)	Scale; heavy filter use

Ingest writes S3 Annotation first; DynamoDB is a denormalized copy. No backfill on enable — re-run ingest.

Enable enable_dynamodb = true when filtered gallery queries return HTTP 503 or when the private bucket grows beyond a comfortable demo size. The API switches to a DynamoDB scan instead of N parallel GetObjectAnnotation calls. S3 annotations remain canonical — see API performance for why filtered reads are expensive without an index.