docs: clarify current runtime vs sealed package evidence

[blackmore-technology-group]

Documentation-only remediation for blackmore-technology-group/ENTITY#91.

• identifies ENTITY v3.4.3 as the current supported runtime;
• preserves the sealed v3.4.0 package payload and historical v3.4.1 requalification context;
• does not invent a v3.4.3 package requalification claim;
• classifies this as a runtime implementation package, not the normative Protocol 1.0 clean-room definition;
• preserves package hashes and release-binding values unchanged.