fix(crypto): add WebCrypto ML-KEM key material

[andrewtdiz]

Summary

• add WebCrypto CryptoKey metadata and usage support for ML-KEM-512, ML-KEM-768, and ML-KEM-1024
• implement ML-KEM generateKey, SPKI/PKCS8 import/export, and AKP JWK import/export using pub plus 64-byte priv seed validation
• report SubtleCrypto.supports() true for ML-KEM generate/import/export and add focused Node 26 parity coverage

Scope

This is the ML-KEM key-material slice only. It intentionally does not implement encapsulateBits, decapsulateBits, encapsulateKey, or decapsulateKey execution; the method surface is handled separately in #4291.

Validation

• PATH="/root/.npm/_npx/bac97da9607b7ef2/node_modules/node/bin:$PATH" node --experimental-strip-types test-parity/node-suite/crypto/webcrypto/mlkem-key-material.ts
• CARGO_TARGET_DIR=/root/perry-worktrees/.build-targets/perry-webcrypto-mlkem-check cargo check -p perry-stdlib --no-default-features --features crypto
• PATH="/root/.npm/_npx/bac97da9607b7ef2/node_modules/node/bin:$PATH" PERRY_NO_AUTO_OPTIMIZE=1 ./run_parity_tests.sh --suite node-suite --module crypto/webcrypto --filter mlkem-key-material
  • report: test-parity/reports/parity_report_20260604_034747.json
• PATH="/root/.npm/_npx/bac97da9607b7ef2/node_modules/node/bin:$PATH" PERRY_NO_AUTO_OPTIMIZE=1 ./run_parity_tests.sh --suite node-suite --module crypto/webcrypto --filter subtle-supports
  • report: test-parity/reports/parity_report_20260604_034800.json
• PATH="/root/.npm/_npx/bac97da9607b7ef2/node_modules/node/bin:$PATH" PERRY_NO_AUTO_OPTIMIZE=1 ./run_parity_tests.sh --suite node-suite --module crypto/webcrypto --filter jwk-ecdh-p256
• PATH="/root/.npm/_npx/bac97da9607b7ef2/node_modules/node/bin:$PATH" PERRY_NO_AUTO_OPTIMIZE=1 ./run_parity_tests.sh --suite node-suite --module crypto/webcrypto --filter jwk-rsa-oaep
• cargo fmt --all -- --check
• git diff --check
• ./scripts/check_file_size.sh

Refs #2518