Deprecated aws_dynamodb_table hash_key/range_key — future aws provider major will break the module (new 1.21.1 resources still use the old form)

[jayyousi]

Describe the issue

The aws provider (6.x) deprecates hash_key/range_key on aws_dynamodb_table in favour of key_schema. Every AFT plan/apply currently emits:

Warning: Argument is deprecated
  with module.aft.module.aft_account_request_framework.aws_dynamodb_table.aft_request_metadata,
  on modules/aft-account-request-framework/ddb.tf line 5
hash_key is deprecated. Use key_schema instead.

Notably, the warning count grew from 2 to 4 with 1.21.1: the newly added aft-customizations-audit table also uses the deprecated arguments — new code is still being written in the old style, which suggests this isn't on the migration radar yet.

Why it matters

Deprecation in 6.x is the pre-announcement of removal in the next major. When that lands, terraform plan fails outright for every AFT deployment until the module ships a fix — and the module currently declares aws >= 6.0.0, < 7.0.0, so consumers can't get ahead of it either. This is the same shape as #630 (module code broken by provider movement within/at the declared constraint range): the affected workspace is typically an organisation's management-account bootstrap, where a broken plan has the worst recovery story.

Expected behavior

Migrate the aws_dynamodb_table resources (four sites incl. the new audit table) to key_schema, ideally before the provider's next major forces it under time pressure.

Environment

• AFT version: 1.21.1
• aws provider: 6.56/6.57 (warning present across 6.x)

Happy to raise a PR — the migration is mechanical and plan-neutral (same key schema, new syntax).