✅ Returns unhashed NWK/LINK keys and hashed transport/load keys as mandated
✅ Throws on unsupported key identifiers to avoid silent misuse
⚠️ Caller must provide correct key material (hashed vs raw) for custom key types
DEVICE SCOPE: Trust Center and any device handling Zigbee key transports
05-3474-23 R23.1, Annex B.1.5 (Key usage definitions)
SPEC COMPLIANCE NOTES: