Add ML-KEM crypto provider

[cobycloud]

Summary

• add a KeyType.MLKEM enum value and register the new swarmauri_crypto_mlkem workspace member
• implement the MlKemCrypto provider with ML-KEM-768 wrap/unwrap and seal/unseal flows plus strict KeyRef validation
• document the package and add async unit tests covering direct usage and CompositeCrypto routing

Testing

• uv run --directory pkgs/core --package swarmauri_core ruff format .
• uv run --directory pkgs/core --package swarmauri_core ruff check . --fix
• uv run --directory pkgs/standards/swarmauri_crypto_mlkem --package swarmauri_crypto_mlkem ruff format .
• uv run --directory pkgs/standards/swarmauri_crypto_mlkem --package swarmauri_crypto_mlkem ruff check . --fix

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https://chatgpt.com/codex/tasks/task_e_68ea2efe53048326924ec134f102f946